View Full Version : The ol' Tahoe is down for the count - coolant in cylinder(s)
arveetek
07-20-2021, 20:54
After 376K faithful miles, the 6.5L in my Tahoe has finally had a major issue. Without any warning, she started blowing a lot of sweet-smelling steam out the tailpipe, and coolant is getting in the cylinder(s) causing it to hyrdolock after shutting it off.
Everything was perfectly normal this evening, and then I stopped for fuel. Upon filling up and attempting to restart the engine, the starter cranked her over for a second and then stopped cranking. I thought it was odd, but figured it was just the starter getting old. I cranked her again, and this time the engine started, but started knocking loudly for a few seconds. That was really odd. She started running normally, so I pulled away from the fuel pumps, looked in my mirror, and saw a huge cloud of smoke. I pulled over and got out, but by the time I got to the tailpipe, it had cleared up. I drove on home (about 4 miles), and then she was smoking again; actually, it was steam. I shut her down, checked a few items, didn't notice anything out of the ordinary, and then cranked her up again. Once again, the starter stopped cranking after a second while making a weird noise. That's when I realized something was preventing the engine from turning over. I tried again, she started up, started shaking and missing, and blowing a LOT more steam!
Here's a video right after I got home:
https://www.youtube.com/watch?v=ExXS6BNtEVM
After this video was taken, it started running horribly and smoking/steaming a lot more. In fact, by the time I drove it over to my shop a hundred yards away, I was wondering if it was going to stay running.
It takes less than a minute after shutting down the engine for the cylinder(s) to get enough coolant in there to hydrolock the engine.
My plan is to pull the glow plugs and then turn the engine over. That should pinpoint which cylinder(s) are getting coolant in them.
What do you think? Blown head gasket? Cracked head? Cracked block? At this moment, there is no coolant in the oil. I released the pressure on the coolant tank, but haven't been able to run the engine to see if there was any noticeable exhaust in the cooling system.
*sigh*
Casey
DmaxMaverick
07-20-2021, 21:14
Down for the count? Don't give up so easy. Most likely just a head gasket. Spend a weekend getting a little more personal with it, and it'll be fine. I'd do whichever side is blown. If you have the time, do both. If it's more than that, cross that bridge when you come to it.
arveetek
07-20-2021, 21:36
Down for the count? Don't give up so easy. Most likely just a head gasket. Spend a weekend getting a little more personal with it, and it'll be fine. I'd do whichever side is blown. If you have the time, do both. If it's more than that, cross that bridge when you come to it.
Thanks for the encouraging words, Greg! I'm not giving up, just a little sad since I don't have a lot of spare time right now. It will be a while before she's up and running.
Casey
Yeah, ID the cylinder(s) causing the problem. No coolant in the oil is a good sign.
trbankii
07-21-2021, 09:55
Sorry to hear. I agree with the others - take a look and hope for the best!
Yukon6.2
07-21-2021, 10:46
If you can afford it, buy a beater for transportation that you can resell after for about the same money.
Then you will not feel rushed to do the job required to make your Tahoe your reliable transportation again.
arveetek
07-21-2021, 12:38
If you can afford it, buy a beater for transportation that you can resell after for about the same money.
Then you will not feel rushed to do the job required to make your Tahoe your reliable transportation again.
That's actually a thought I had... the wife isn't too keen on the idea, though! :D
Casey
Even beaters are commanding top dollar these days.... I just had to replace one of our daily drivers and it's a tough market out there. Most of the ones I was really interested in were sold before I could get there to look at them.
Been through this game a few times.
Personally I would just get the engine out of the rig......It's not that bad of a job to yank it out.
Than you can get it apart fast and easy.
Head gaskets as mentioned are the likely suspects......
My bet would be one of the two front cylinders where the coolant lays right on the deck and over time causes the gaskets to corrode and finally fail.
Both of mine had eroded the block deck enough that we had to machine off .015" from the decks and use the thicker Felpro gaskets.
One thing....With the engine out you can wash the engine bay well and do a really spiffy job making it look all new again.......
Just an FYI
No doubt so antifreeze has gotten into the crankcase and the oil.....Glycol is tough on a lot of parts...
Unless you are planning on replacing a lot of things......Maybe drain the coolant completely, drain the pan and get a fresh oil and filter....then run the engine long enough to purge out the crud.
When I did mine I tossed the lifters in the trash....and with the rebuild it got new bearings anyway...
Good luck....
Waiting to see pics of job as it progresses
arveetek
07-22-2021, 06:24
I've been working sun up to sun down this week, so haven't had much time to diagnose anything, but a quick check of the oil level last night showed the oil level had doubled, and the coolant level had dropped. That's not good. Would a blown head gasket or cracked head allow that much coolant to get into the oil pan just from sitting overnight? I'm hoping it's not a cracked block.
I will have time this weekend to tear into things and really find out.
Casey
My Suburban blew the gasket on the front of number 2 cylinder (Where I was talking about) and it filled the engine chuck full of Glycol)
The close proximity of coolant that just lays on the deck and eventually soaks into the gasket causes erosion of the fire ring area and over time the block deck etches out and leaves an actual little divit in the deck...
Once this happens the gasket fails.
With the amount of coolant we are talking....this is my best guess...
When our Burb did it I hit the starter and the engine hydro locked and the starter fell off.
Bolts broke...block was fine...lucky shot...
Get it out and then you can do the post mortem easily..
Myself I like to yank the turbo and manifolds off the engine as this makes getting the engine out easier.
Get the RH front tire off and the rubber inner flap off....This gives gobs of room to get in and remove the exhaust manifolds, the turbo drain pipe, the starter electrical connections and the front starter support ....all this stuff with far less fight and busted knuckles.......
Get the fuel manager off the rear of the engine to gain access to electrical plugs and the bell housing bolts.
GET A 9/16" FLEX HEAD GEAR WRENCH.....TO DO THE UPPER TRANNY BOLTS.
Your rig should have SAE bolts....96 and later used metric in this location.....
A totally factory install has stud top bolts with lock nuts to secure the fuel feed and return pipe bracket to the top two bolts on the tranny.... (If the bolt comes loose while removing the nuts holding the fuel pipe brackets it can require grinding down an open end wrench to hold the bolt head at the block)
This lash up with the fuel pipes is a POS and can be a PITA
The other tranny bolts are easily accessed from under the rig while getting the bottom bell housing cover off....and the starter....
Just an FYI
My rig was down for some time while I did the rebuild....The Glycol had caused the turbo to stick.
To stop this issue ....Flush the turbo oil passage out with solvent or gasoline...both the oil feed passage and the exhaust passage through the hot side.....Dry and then add oil to the oil feed line and store the turbo until you need it...
Remember....the engine oil cooler is likely contaminated too......Remove the radiator (Usual thing when getting the engine out) flush the radiator and the oil cooler.
I used GUNK foam engine cleaner in the oil cooler...then water to wash it out.
Then solvent or gasoline to finish it off..
Blow out the lines and let dry.
I like to leave the AC system intact.....just tie off to the inner fender with bungy strap or ????
Stick a piece of plywood or??? in the protect the condenser core.
All the wiring is pretty much ...such the the plugs are not interchangeable.. Mark them if you wish....
The oil cooler lines at the engine are a "Snap in lock type fitting" You can wrench the block fittings off and fight the lock rings later.
Unless the oil lines are recently new....Replace these with either a new factory type or a set of braided type lines with JIC fittings.....
These are not pleasant to replace with the engine in the truck.
I usually unhook the oil lines at the radiator and leave them on the engine.....Install new on the engine and then it's easy to reconnect later.
Fighting things is something I avoid at all cost....Because if it's a PITA to get to or work on....it just might leak or ????? later.
The inner fender access point on the RH side will allow you very easy access to the glow plug tubes and wires and manifold bolts.
Installing the manifolds after the engine is set makes life easy.
Remove the lower RH motor mount from the frame pad before you lift.
Easy to do and this allows the engine to be shifted slightly to the RH side and then barely off the frame and its out.
Otherwise some rigs have settled enough (Body mount sag) the the rear of the engine will hit the firewall before the motor mounts clear the frame brackets.....and life gets ugly.
Just reverse the procedure going back.
Remove the six nuts on the converter to flex plate and shove the converter back into the tranny a bit....Good to go.
Ply wood chunk across a floor jack under the tranny pan before you lift the engine..
A couple long 3/8 bolts into a couple tranny bolt holes and stick a piece of 2 x 2 wood (Twig) across the fame and set the tranny down on them.
All snug as a bug in a rug until its time to replace the engine.
Now this is me (Very anal) I grab a box of Sandwich bags and "Tag and bag" all groups of bolts as I go and label them.
This makes the return far easier and the right bolts go back where they came from.
It is nice to be able grab a bag of bolts/nuts and have what you need for the area you are working on..
Really a pain when you toss everything into a bucket and then try to sort it out weeks or months later.
I put all my bags of bolts and such in a box in sort of the order I will need them going back.
Bags and a sharpie pen.... yessssssssssss....
I have done several of these rigs and done it with the tag and bag program ....never ended up short or long on parts.
And things look like Ma General had it .
TAG'EM AND BAGE'M ..
Good luck......
arveetek
07-22-2021, 08:18
Thank you Robyn! I'm glad to hear it could still possibly be just a head gasket. Did you have the block decked to get rid of the erosion issue?
I ditched the factory fuel manager several years ago in favor of a Racor fuel filter, and I replaced all the fuel hoses with aftermarket hoses. I cut the factory lines at the back of the block, so all that's left back there is a couple of short pieces bolted to the block, so I won't have to fight with all that. I also have steel-braided oil cooler lines installed already.
Casey
Yes...I stripped the block down and sent it to the machine shop and we cut the decks.. .010" as recommended did not clean so we went to .015" and got clean metal.
We did both sides the same to keep the compression ratio balanced
Sadly the engine needs to come all the way down to bare bones, cam bearings and all oil passage plugs out....then hot tanked and then machined then rewashed ...
Best plan IMHO is to yank the sucker out and then open it up and see wassssup. My bet is either cyls 1 or 2
JUST A LITTLE HINT.
I have no idea what you have been into...so..
When removing the injector lines
Mark the pairs as to 1-3...5-7 LH and 2-4...6-8 RH and keep them in pairs..connected with the factory clamps.
Make a map of the DS4 rotor head connection as to where the lines all fit.
There are two lines that can be swapped....They run like crap this way....Ask me how I know this....then ya have to rip it apart again. A crow foot and a 3/8 breaker bar work sweet to get at the pump lines.
Take a real good look at the electrical harness that lays in the valley to connect to all the engine connections.
These do get ragged after many years and miles.....Replacement with new may still be possible....IIRC the after market has these harnesses available.
A pain to replace with the intake on......
DmaxMaverick
07-22-2021, 10:18
The best way to do it is certainly to pull the engine and strip it down. However, if time and resources are limited, I suggest not doing that, just yet. Identify which side is the trouble, strip the top/front of the engine down (remove accessories, turbo (if passenger side issue), intake, pumps, etc.), and remove that head. See what you have to deal with. Whatever you find on one side, will likely be similar on the other, so keep that in mind. If you need to pull the block, it's much easier with the heads out of the way. If the block deck is good (a coin toss), deal with the head (repair/replace/clean up) and reassemble with new gaskets/bolts. The engine is a high-miler, so pulling it should mean a full overhaul. If you aren't interested in that unless necessary at the moment, minimize the efforts and time. Definitely fully flush the fluid systems ASAP to eliminate the cross-contamination, and preserve them for duty when that time comes. Time is very important, as the glycol, water, and additives can damage bearings, lubricated friction surfaces and such in a short time. Make it a priority.
arveetek
07-22-2021, 11:32
I have no idea what you have been into...so..
It's been about 15 years since I've done major engine work. Back then it was when I yanked my 6.2L out of my '81 C20 project to replace a bad lifter; the "Might as Wells" resulted in a fully customized 6.2L that was bored .040 over with custom, ceramic-coated lower-compression pistons, all new fuel delivery system, stud girdle, timing gears, etc, etc. But it's been a few days since I've done anything like that, so I sure do appreciate the tips!
Casey
arveetek
07-22-2021, 11:34
Identify which side is the trouble, strip the top/front of the engine down (remove accessories, turbo (if passenger side issue), intake, pumps, etc.), and remove that head. See what you have to deal with.
That is exactly my plan. I want to discover what the issue is, and THEN step back and form a game plan.
Casey
Also....very important.....BE VERY SURE TO CHECK THE POSITION OF THE PISTONS WHEN AT TDC
The pistons should be at DECK HEIGHT TO .005 PROTRUSION ABOVE THE DECK
Most engines will be at deck height.
If you end up cutting the decks you do not want to find out that they have already been cut before.
BEEN THERE DONE THAT....UGLY...
Yukon6.2
07-23-2021, 10:19
[QUOTE=Robyn;332102]Also....very important.....BE VERY SURE TO CHECK THE POSITION OF THE PISTONS WHEN AT TDC
The pistons should be at DECK HEIGHT TO .005 PROTRUSION ABOVE THE DECK
Most engines will be at deck height.
When i pulled the heads on my first GM Diesel a 6.2 i found a piston that sat lower that the rest.
The rod got bent at some point years befor i got it.The piston sat a bit lower than the rest.I changed the rod and cut the ridge from the cylinder.
It ran for years with one hole that would smoke a bit at start.I always assumed it was the one that had the bent rod.
If you end up cutting the decks you do not want to find out that they have already been cut before.
When ya get this old stuff apart you can uncover all sorts of mischief ......yeah buddy
arveetek
07-25-2021, 19:44
Update: Pulled all the glow plugs. On the passenger side, the first three cylinders were dry. The number 8 plug was wet, and when I removed the plug, coolant dribbled out of the hole. I then proceeded to the driver side, and the first two plugs were dry, number 5 was damp, and number 7 was really wet. In fact, when I pulled that plug, a lot of coolant came out, and continued to drip coolant for some time (even after draining and removing the radiator).
Cylinder 8 glow plug removed:
https://live.staticflickr.com/65535/51336142219_3ed776920b_c.jpg
Cylinder 7 glow plug removed:
https://live.staticflickr.com/65535/51336142204_65f41048b0_h.jpg
This is the amount of coolant that drained out of cylinder 7 after removing the glow plug:
https://live.staticflickr.com/65535/51334688072_80a2a6a4eb_h.jpg
I was confused to find coolant in both rear cylinders; I would have expected to find it one side of the engine, but not both; I started wondering if there was a block issue?
I went ahead and proceeded with removing the driver's side head since cylinder 7 seemed to be in the worst shape:
https://live.staticflickr.com/65535/51336142199_640d0f563d_h.jpg
https://live.staticflickr.com/65535/51335630833_a56facaeae_h.jpg
https://live.staticflickr.com/65535/51336142159_e38628703b_h.jpg
The head gasket on cylinder 7 was obviously blown out into the water jacket on the rear of the head:
https://live.staticflickr.com/65535/51335630773_1d0cb46f48_h.jpg
I can't hardly get my head into cylinder 7, but so far I don't see any cracks or catastrophic damage. In fact, I was shocked to see how clean the cylinders and pistons were! There's not even a ridge at the top of any of the cylinders.
I have decided to go ahead and pull the engine the rest of the way out; at this point, the only thing left holding it into the vehicle are the motor mounts and the transmission. I might as well get it out on the stand where I can do a proper head gasket job. Also, the passenger side exhaust manifold bolts are in such poor shape, I'm not sure I can get the manifold out without a lot of cussing. It will be easier to pull the engine and work on the exhaust manifold then.
At this point, assuming I don't find major block issues on the passenger side after pulling that head, my plan is to pull the oil pan, check a few bearings, and if all looks good in the bottom end, I will then throw in a new oil pump, rear main seal, and install new head gaskets. I might as well replace the injectors while it's easy to do, and perhaps upgrade the turbo to an HX35. I will also take the opportunity to replace the torque converter, since lately I've noticed it slipping when towing my camper. That is really as far as I want to go; I don't want to do a full rebuild if not needed.
Casey
DmaxMaverick
07-25-2021, 20:28
That's a dirty engine (typical, really), but I like what you've found. It is definitive, which is what you want. No mysteries. Be optimistic about the rest.
Add a set of bearings to the list, since you're going in. They're relatively cheap, and the miles justify it.
I agree with Maverick on the bearings.
Keep in mind....The 6.5 uses "Select fit" bearing shells......Generally these are not available in the after market....Std, -.010", -.020" and -.030 for grinding the crank
Don't be shocked to find upper and lower shells with different size markings...
The bearings will be marked as to what they are....
I have used the Stds in places where select fit came out. A good shot is .0025" clearance.....
Just an FYI
Great deals can be had on top name brand bearings and other parts on ebay...I saved big $$$$$$$$$$$$$ when I did the Dahooooley back a few years ago...
Get things apart and then get your parts coming......By the time you need the stuff you will have it in hand.
I am still puzzled at how coolant got on both sides of the engine........????????????????????
A set of engine tech Rod bearings....$30
https://www.ebay.com/itm/274546090212?hash=item3fec38e0e4:g:GxEAAOSwvdJfoKL N
(https://www.ebay.com/itm/274546090212?hash=item3fec38e0e4:g:GxEAAOSwvdJfoKL N)
I have used this brand several times......About like what we used to call "White box" rebuilder parts.
I used this stuff on Dahooley and the Burb rebuilds.
I have a set of this brand sitting in the wings for my 406 cat engine.
Careful shopping can yield great cash savings and get good parts too..
https://www.ebay.com/itm/232520986118?hash=item362354ae06:g:W6YAAOSwlndZC1d k
I am still puzzled at how coolant got on both sides of the engine........????????????????????
Open intake valves? If all three cylinders have open intake valves and coolant under pressure is being forced into #7... Is the intake manifold wet?
DmaxMaverick
07-26-2021, 07:40
Open intake valves? If all three cylinders have open intake valves and coolant under pressure is being forced into #7... Is the intake manifold wet?
Certainly possible. A perfect storm. Cylinders 8 and 7 are adjacent in the firing order and on the same journal, allowing both intake valves open at the same time. It may explain a condition if the other bank doesn't appear to be compromised.
I have not heard anyone mention the rings. If you are going this far down I would replace those due to experience. I replaced heads on a small block Chevy after a valve job and the oil consumption caused clouds of blue smoke. Since the valves sealed properly the weak rings allowed much blowby through the PCV and burned with the fuel. Not much additional $$ for piece of mind.
DmaxMaverick
07-26-2021, 09:11
I have not heard anyone mention the rings. If you are going this far down I would replace those due to experience. I replaced heads on a small block Chevy after a valve job and the oil consumption caused clouds of blue smoke. Since the valves sealed properly the weak rings allowed much blowby through the PCV and burned with the fuel. Not much additional $$ for piece of mind.
SOP for gassers, for sure. 376K miles on a Diesel with no cylinder ridge (very typical of most 6.2/6.5)? I wouldn't touch them unless there is some other indicator. I've never replaced the rings on a Diesel engine I didn't bore unless there was some other reason.
I hate to toss cold water on the camp fire....but I will cast a dissenting vote.
I have yanked 6.2/6.5 down and found the rings pretty well stuck up...
I would vote to yank the slugs out...Clean them up well.
Use a bottle brush hone on the bores lightly and toss in a fresh set of moly rings.
This will give the best the little beast is going to do.
If the pan is off and the bearings are going to be out....An extra days work at most and the job will be a better one..
With the pan off....Timing set, seal and fresh gaskets would be smart too...
The talk was to replace the rear main seal.....
If it were me I would buff the head surfaces with the big 9" wire wheel to get the crud off..
Then pop out the valves and have a peek see.....EGR engines are notorious for clogging up valve pockets with carbon....
This junk falls off and can cause issues.
Look at the valves and seats....maybe lap them lightly with compound and call it a day.
Fresh valve seals would be a good idea....
It is hard to yank an engine out and not tend to some basics......
arveetek
07-27-2021, 07:27
This was me at 11:00 pm last night:
https://live.staticflickr.com/65535/51339710420_f496bb497f_c.jpg
I am tired and sore. And the bummer is that I won't have much time to work on it in the next two weeks! :(
Casey
LOOKS VERY VERY GOOD to see the beast hanging on the lift.....
Looking forward to seeing what else presents itself in that critter...
Ahhhhh
Take the time to make a sharp scribe line across the injection pump flange and the front cover at the top before you remove the IP ....
Align the marks when you put the IP back on and it will go right to work and no other fooling will be needed.
The computer will remember where it last found things and it will be happy...
Yukon6.2
07-27-2021, 09:36
Working on things when you would rather be doing something else
That was me the Christmas of 2019,the wife at the time and my Daughter decided to have Christmas without me on the other side of the country
So instead of sitting in a house alone i pulled the 7 speed tranny out of my 2004 7500 Topkick
arveetek
07-27-2021, 09:40
Take the time to make a sharp scribe line across the injection pump flange and the front cover at the top before you remove the IP ....
Align the marks when you put the IP back on and it will go right to work and no other fooling will be needed.
The computer will remember where it last found things and it will be happy...
I'm hoping to leave the pump alone. I replaced the timing chain, water pump, and balancer 3 years ago as preventative maintenance.
Casey
Copy that.....
But if you end up removing it.....just a great way to eliminate problems.....
More Power
07-28-2021, 07:33
Casey,
You've identified the cause as being head gasket failure... Most likely, a result of just end of life... sorta like the head gaskets on my '01 GMC. As long as you can't identify any other damage, I'd inspect the heads (for fire-ring wear groove, flatness, cracks, etc), and if good just clean them up, and re-install with new Fel-Pro head gaskets and Fel-Pro TTY head bolts. Remember that Fel-Pro produces +.010 over head gaskets for heads/blocks that have been decked. If you need it, send me your current mailing address, and I'll send you the current Troubleshooting & Repair Guide, which will walk you through the process of how I did our 6.5TD Power Project engine assembly - including head gaskets.
arveetek
07-28-2021, 10:02
Casey,
You've identified the cause as being head gasket failure... Most likely, a result of just end of life... sorta like the head gaskets on my '01 GMC. As long as you can't identify any other damage, I'd inspect the heads (for fire-ring wear groove, flatness, cracks, etc), and if good just clean them up, and re-install with new Fel-Pro head gaskets and Fel-Pro TTY head bolts. Remember that Fel-Pro produces +.010 over head gaskets for heads/blocks that have been decked. If you need it, send me your current mailing address, and I'll send you the current Troubleshooting & Repair Guide, which will walk you through the process of how I did our 6.5TD Power Project engine assembly - including head gaskets.
That is my plan! She was running great with no issues, no abnormal smoking, no blow-by, etc. No symptoms to make me think it needs a head job or ring job.
I need to look and see if I have that guide, I don't recall. I've got several of the DP books. I will let you know. Thank you!
Casey
arveetek
08-15-2021, 13:57
I haven't had much time to work on the ol' Tahoe lately, but this afternoon I finished my tear down to inspect the bottom end. The bearings didn't look too bad for 375K miles, and I'd be tempted to run it as is, but I did find something that gave me pause for concern - there's a typical crack in the block originating from the outer main bearing hole on main cap # 4, on the cylinder 7 side. It's about an inch long:
https://live.staticflickr.com/65535/51380709463_bc2805b181_c.jpg
https://live.staticflickr.com/65535/51381482495_3f2c0ecbc5_c.jpg
https://live.staticflickr.com/65535/51381230604_77599f1377_c.jpg
https://live.staticflickr.com/65535/51381256104_d1255b26cb_h.jpg
So the question is now what should I do? I assume it would not be wise to continue running this engine with the crack, correct?
This is a 1995 929 block with 376K miles. I also have in my possession a 1997 506 block with around 100K miles; however, there is some issue with that engine - when I pulled it, it was running, but had no compression on cylinder 1. I never tore into it to see what the problem was. I am guessing it would be prudent at this point to go ahead and tear into the 1997 block and see what it looks like to see if it's a good candidate for a rebuild....
Casey
You can install one of the LOCK AND STITCH inserts in the cracked hole....
At 375K
Myself, I might be quite willing to clean things up, install fresh head gaskets and run it until it gives up again.
Unless that crack gets into a cylinder wall or worse it's not going to hurt much...
Knowing when it got there is not possible....
50K miles...100K miles, 200K miles....Maybe sooner or later....
I have torn into six and a half's with under 100K miles that were a cracked mess....
Don't lay awake nights trying to figure it out...
NOTE...NOTE....NOTE
IF you go with the 97 block....THE BELL HOUSING BOLT THREADS ON THE 96 AND LATER ARE METRIC.
The 95 was the last year that used SAE threads ON THE 6 BOLTS BACK THERE
The 3/8 bolts will thread into the metric hole....but will not hold.....
Doing the LOCK N STITCH inserts is not hard....and they do pull the area together.
Are the outer holes the large or small bolts ????
arveetek
08-15-2021, 18:52
You can install one of the LOCK AND STITCH inserts in the cracked hole....
At 375K
Myself, I might be quite willing to clean things up, install fresh head gaskets and run it until it gives up again.
Unless that crack gets into a cylinder wall or worse it's not going to hurt much...
Knowing when it got there is not possible....
50K miles...100K miles, 200K miles....Maybe sooner or later....
Are the outer holes the large or small bolts ????
I was wondering about that... no telling how long the crack has been there. It could go a long, long time as is. The outer bolts are large - same diameter as the inner bolts.
Casey
If everything else is good....I would say that installing the insert would be a good idea if you were going to spend time and $$$ to do a serious refresh on the engine.
If you are still thinking about just patching it up and then back together.....Run it as is.....
Doing the insert means stripping the block down all the way so you can get tools on it to drill out the hole and install the insert.
The chips and such from the job require careful cleaning afterwards to make sure none of the junk gets into the inner workings.
I did a couple blocks a few years back.....I machined up a steel plate that has openings for each of the outer main bolt holes and the plate fastens to the pan rail holes.
I used a magnetic drill press to drill the holes.
Simply use a steel rod that will just slip into the threads (I grabbed a hardened transfer punch that just slid past the threads) Stick the rod in the drill chuck and align the drill to the hole. .....Use the drill provided in the kit.... drill the hole out and down to the prescribed depth...Tap the hole deep enough that the insert will thread in tight and so the top of the insert is Flush to .002" below the main web mating surface....
Clean the hole with Brakleen and blow dry...Do one last final check fit.....Clean the hole and insert and dry....add loctite RED and tighten that bad boy up......
After this two small holes are drill along side the insert and hardened pins are driven in to permanently secure the insert so it can't unscrew.
Very simple procedure to do.....
The other choice is to find a shop that can do it that has a milling machine large enough to sit the block on the table...
If the block is otherwise good....A great save.
Or....Check out the 97 block and see wassssup there.
The 97 block is likely a squirt block and will have smaller outer bolt holes.
SQUIRT BLOCKS USE A HIGH OUTPUT OIL PUMP.....YOU MUST USE THE PROPER PUMP OR THE OIL PRESSURE WILL BE NEAR ZIP AT IDLE
I happened to have a large mag drill so the choices I made were based on that....
This can't be done free hand.....a good mag drill will do it.
The steel plate was simply a means to attach the mag drill to the block.
Most drill press tables are not large enough to handle the block.
If you get hot on the 97 block.....Clean it good and make sure it is not cracked.
Besides the main cap bolt holes.....carefully check the oil squirt holes in the main webs for cracks too.
Some early squirt blocks (506 blocks ) had larger oil squirt nozzles in them and the holes would crack into the main webs and into the cylinder wall at the bottom.
Be sure to remove all 8 squirt nozzles and replace them after cleaning just before you drop the crank in..
If one falls out...you have a huge oil leak.
The squirt nozzles are a small aluminum piece with a tiny hole in the end facing towards the cylinder. Small end of the nozzle goes toward the cylinder.
Usually the nozzles can be removed with a small hard wood dowel and a plastic hammer and tap them back towards the main saddle.
Keep us in the loop.....
Lots of options..
arveetek
08-16-2021, 05:57
I definitely don't have the skills or tools to do the insert repair myself. I was bummed when I found the crack since I knew that meant stripping it down to a bare block and then hoping to find a local machine shop able to make the repair. More down time that I wasn't planning on.
I think my next move is to tear into the 97 engine and see what she looks like inside. If that doesn't pan out, I'm leaning towards slapping some head gaskets in the 95 engine and moving forward as is. Then start looking for a replacement engine to a complete, thorough rebuild on as time allows. I need my vehicle back on the road more than anything; I can't afford much more down time (and now is not a good time to be looking for a used truck!).
Thanks!
Casey
I fully understand.....
Clean it up...Stuff a set of gaskets in that sucker and run it like ya stole it....
Personally under the circumstances I would not worry too much about that crack.
If the head gasket had not gone away....we would not be having this conversation...:rolleyes:
arveetek
08-18-2021, 15:57
Last night I was able to get the 1997 506 engine disassembled to see what was up inside that motor. It was running when I pulled it out of the C3500 truck it was in several years ago, but had almost zero compression on one cylinder and was missing.
Turns out the engine must have ingested a glow plug; the piston top was beat to heck and the exhaust valve was damaged with a chunk missing out of it:
https://live.staticflickr.com/65535/51387202646_a332743e13_b.jpg
https://live.staticflickr.com/65535/51388207635_1382e9faa5_b.jpg
I put a light in the exhaust port.... there shouldn't be light shining out behind the valve!
https://live.staticflickr.com/65535/51387935369_9b21e4f1fd_b.jpg
The rest of the engine looked great! No cracks that I can see. The cylinders still show the cross-hatch marks:
https://live.staticflickr.com/65535/51387202616_78dbb436c1_b.jpg
The only issue I have found so far is that the cylinder with the damaged piston has some very light scoring:
https://live.staticflickr.com/65535/51386442042_d28fd4f878_b.jpg
My plan is to remove that piston and hone that cylinder to see if it will clean up. If so, I will then use this short block, swap a piston in from my 95, use my 95 heads, install new bearings, rings, and headgaskets, swap over my nearly new water pump and timing chain from the 95, and then I should be good to go.
Casey
arveetek
08-21-2021, 08:05
Is it a Squirt block ???
Yes it is!
https://live.staticflickr.com/65535/51393489345_54f607495d_b.jpg
I went ahead and pulled all the pistons and removed the crankshaft so that I could really inspect this block, and there are no cracks anywhere. (I read another post where one guy didn't find any cracks until after taking the crank out, so I wanted to be real sure.) The only issue is cylinder one has some slight scoring.
This is after after I honed the cylinder for a few minutes:
https://live.staticflickr.com/65535/51392481591_a2ef9c1e8c_b.jpg
I've almost got it honed enough to where I can't feel the line anymore. I'm going to keep working on it, and as long as I can't feel the line, it should be good to use, correct?
Casey
Yukon6.2
08-21-2021, 10:10
Myself i probably would stop where you are.
As you hone you are making the bore bigger and losing some of the compression ability of the rings.
The small imperfection that is left will probably fill with carbon and be a moot imperfection.
arveetek
08-21-2021, 19:22
I went ahead and honed the cylinder a bit more, and she cleaned up real nice!
https://live.staticflickr.com/65535/51394666675_e6759a9c04_b.jpg
I then checked the cylinder diameter by measuring the piston ring end gap, and she was still within specs:
https://live.staticflickr.com/65535/51392889972_2321eb72a0_b.jpg
I then moved my attention back to the heads. My intentions were to use my original 1995 heads, but upon cleaning them up, discovered they were cracked between all the valves in all 4 spots on both heads:
https://live.staticflickr.com/65535/51393656456_bfa2b916ba_b.jpg
https://live.staticflickr.com/65535/51394666725_a925bbceaa_b.jpg
https://live.staticflickr.com/65535/51392889997_e6878603b4_b.jpg
So then I decided to clean up the 1997 heads, and was pleasantly surprised to find no cracks at all. These heads even had the diamond pre-cups:
https://live.staticflickr.com/65535/51394666715_664888c680_b.jpg
https://live.staticflickr.com/65535/51393918813_5b36ed59ab_b.jpg
The only issue with the one head is where cylinder 1 ingested a glow plug and banged up the head and damaged the exhaust valve:
https://live.staticflickr.com/65535/51394387504_7dfa4447ef_b.jpg
Luckily the valves in the 1995 heads are in great shape, so I can use those valves. I will lap all the valves and put in new seals.
This area is pretty banged up, but since the firing ring area where it seals to the block is fine, this shouldn't affect anything, correct?
https://live.staticflickr.com/65535/51393918838_4dd29ab2d4_b.jpg
So things are looking up. This 506 block out of a 1997 C3500 utility truck with low miles looks really good. New rings, bearings, head gaskets, head bolts, seals, and an oil pump and I should be good to go. I'm about ready to start ordering parts (finally!!).
Casey
DmaxMaverick
08-21-2021, 19:52
The 95 heads don't look that bad. Cracks between the valves are common and aren't a problem if they don't leak. The 97 head in the pic needs a date with the mill. The impact damage probably won't be an issue, but it needs to be cleaned up and true.
I would look at the valve seats in the 95 heads....If the seats are not cracked....run them...
The 97 block looks great....
As I mentioned before...be sure to run the 97 oil pump (High volume)
Check the deck on that banged up head.....If it is flat....I would use it as is....A good "True" straight edge and a skinny feeler gauge.....see if it is warped....
Cutting the head is quite doable....But on the 6.2/6.5 the valve recess is important....Cutting the heads can lead to starting issues.
I am not sure why this is...but IIRC after reading a service bulletin some years back....I read about this anomaly...
I have run heads that make yours look pristine........
Also I would say to replace the one valve with a fresh one and lap it in....The others are all happy.... If it ain't broke ya know... Just clean things up and remove any carbon buildup on the valve heads.....Then check the seat contact with prussian blue... (https://www.google.com/aclk?sa=L&ai=DChcSEwipxJra0cTyAhUHC60GHYRMDl4YABAEGgJwdg&ae=2&sig=AOD64_2rkg1rkrLR0VwJwjXk6hdNfiKzrA&ctype=5&q=&ved=2ahUKEwiZo5La0cTyAhUeHDQIHc9mACsQ9aACegQIARBB&adurl=
If the contact is good....run it. Really no sense in making yourself more work.....
With the seat clean and a thin smear of blue on the valve seat....Slide the valve in an lightly Tap it on the seat.....Look at the contact pattern on the seat and act accordingly.
I am nervous about that one seat after getting thrashed as it did.
Looks good
Should prove to be a pretty good engine .....
(ADDITION)
I found this excerpt from an article that spoke of the valve recess
Pushrods for this engine are specific in their orientation in the engine. They have a very specific difference in their hardness from end-to-end. The side with a paint stripe or copper coloring must go to the rocker arm side or the top of the engine. Failure to install the push rods correctly will result in premature engine failure without question. Valve recession for both the intake and exhaust valves is .034″ – .048″ – being outside of these specs will result in hard starting, white smoking and/or runnability issues.
arveetek
08-22-2021, 15:12
The 97 head in the pic needs a date with the mill. The impact damage probably won't be an issue, but it needs to be cleaned up and true.
Yes, I agree. I have the heads loaded up and will get them to the shop this week.
I am nervous about that one seat after getting thrashed as it did.
Looks good
Should prove to be a pretty good engine .....
I found this excerpt from an article that spoke of the valve recess
Valve recession for both the intake and exhaust valves is .034″ – .048″ – being outside of these specs will result in hard starting, white smoking and/or runnability issues.
Thanks for the info. I decided to take the 97 heads to the shop to have them resurfaced and have them go through the valves.
The block deck is nice and flat; the heads... not so much. I think they're within spec, as my GM service manual says .006 is acceptable, and I measured .005 warpage. But there's some pitting I don't care for, and it makes me nervous to try and run them as is.
I also came across this in my GM service manual:
https://live.staticflickr.com/65535/51396562599_3914603493_b.jpg
I know that resurfacing can be done (I've done it with success on my old 6.2L), but would I be wise to get the .010 thicker gasket from Felpro to make up for the milling on the heads?
Casey
"Valve recession for both the intake and exhaust valves is .034″ – .048″ – being outside of these specs will result in hard starting, white smoking and/or runnability issues." Reads like something from GM and I have no doubt it's accurate and from real world testing. I just don't see how valve recession outside those limits would cause those problems. If they were recessed a little too deep, it would lower compression at TDC and cause hard starting? Surely it couldn't lower compression to that degree with a small amount of recession outside those limits? And white smoke is unburnt fuel. A little extra valve recession causing incomplete combustion?
Been there...done that...It is real.
I can't tell you why....But GM likely would not spend the time and effort to print it if it was of no value.
Taking off a bare minimum should not hurt.... BARE MINIMUM .002" OR SO and be sure the valve recess is within spec.
DmaxMaverick
08-23-2021, 06:30
Using the +0.010" gasket won't hurt anything, and would certainly account for any concern about the height. If the engine or heads have been previously messed with, be sure that's not where you are already, or worse (Robyn can comment on that). Can you read the label on the old gasket? are there any scribe/stamp marks on the block deck or head? Definitely measure piston crown and head height to confirm.
OHHHHH YEAH BUDDY
Get the crank in (Only need a couple bearings) one piston/rod assembly "No rings needed"
Run the pistons to TDC and check the piston to deck location.
Should be flush with deck to .002" or so above
I had a block that had one side decked at .010....I bought the "Crack free block" from a rebuild supplier.... ASSUMED THE BLOCK WAS AS MANUFACTURED (BAD PLAN)
We decked the block .015" to clean it up......At assembly one side had the pistons hanging out of the block .025" OH !@#$%^
That ended poorly.
Bought a special MLS gasket to fix the issue.
Lasted a year and started leaking pressure to cooling system.
Ended up building a fresh AMG block (Another long story)
Just verify where the pistons are in relation to deck....and be happy......Too many engines get massaged and nothing is stamped on the upper deck flanges.
Never assume anything on these things....it can turn ugly and get $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$$$$$$$$$
arveetek
08-23-2021, 07:57
Get the crank in (Only need a couple bearings) one piston/rod assembly "No rings needed"
Run the pistons to TDC and check the piston to deck location.
Should be flush with deck to .002" or so above
I had a block that had one side decked at .010....I bought the "Crack free block" from a rebuild supplier.... ASSUMED THE BLOCK WAS AS MANUFACTURED (BAD PLAN)
We decked the block .015" to clean it up......At assembly one side had the pistons hanging out of the block .025" OH !@#$%^
Bought a special MLS gasket to fix the issue.
Lasted a year and started leaking pressure to cooling system.
Ended up building a fresh AMG block (Another long story)
Just verify where the pistons are in relation to deck....and be happy......Too many engines get massaged and nothing is stamped on the upper deck flanges.
I remember that whole ordeal!
I assume this engine has not been touched; I pulled the engine myself from a low mileage 1997 C3500 city utility truck. But, we all know what ASSUME means..... :D
Thanks again for all the advice!
Casey
More Power
08-23-2021, 13:01
I remember when I had the engine shop do the machine work on our 6.5TD Power Project engine, that the valve guy said he returned the geometry of the valve train to stock after decking the heads and block by trimming the valve stems. I don't think the +.010 Fel-Pro head gaskets were available then. I agree with DMaxMaverick, the head decks look like they need to be machined.
I had a 6.2L head back in the early 1990s that had one combustion chamber where coolant/water had eroded the cast iron, making it look like the deck area on the head you have here. We/they just did the machine work on it, and we re-used it. Not a problem...
Jim
arveetek
08-24-2021, 18:28
Can you read the label on the old gasket? are there any scribe/stamp marks on the block deck or head?
The gaskets off the 1995 engine are FelPro 14098623. The gaskets off the 1997 engine are FelPro 12554979. I haven't discovered any scribe or stamp marks yet.
Casey
DmaxMaverick
08-24-2021, 20:07
Those are GM part numbers. Are you sure they're Fel Pro? Fel Pro item numbers are 5 or 6 digits, usually with a letter.
arveetek
08-25-2021, 04:43
Those are GM part numbers. Are you sure they're Fel Pro? Fel Pro item numbers are 5 or 6 digits, usually with a letter.
Yes, they are definitely stamped with the FelPro name:
https://live.staticflickr.com/65535/51402730300_a4e388093e_b.jpg
https://live.staticflickr.com/65535/51402510634_6a1e62aa0b_b.jpg
https://live.staticflickr.com/65535/51401004617_c613ef792c_b.jpg
https://live.staticflickr.com/65535/51401751216_695022dcb2_b.jpg
https://live.staticflickr.com/65535/51402013673_3fe990ebb2_b.jpg
Casey
arveetek
08-28-2021, 15:43
I'm trying not to let the "might as wells" get out of control, but I have noticed lately that the torque converter was slipping a bit when locked up, especially when towing. I had planned on tossing in a new torque converter while the engine was out, but after a 30 minute phone call with my transmission guy this happenend......
https://live.staticflickr.com/65535/51409820745_52d19c6bb7_b.jpg
I mean, 376K miles on a 4L80E is pretty darn good. It will be way easier to rebuild it now, and probably cheaper. If I wait until it fails, it could grenade and cost a lot more to rebuild.
*sigh*
Oh well... when this is all said and done, I should have a reliable rig to get me down the road another 300K!
The heads are currently at the machine shop; hope to have them back next week.
I just ordered $1500 in parts today - rings, bearings, gaskets, motor mounts, injectors, starter, etc. Pretty much everything will be new in the drivetrain except for the power steering, alternator, and A/C compressor (compressor is only a few years old, as is the alternator; I've never touched the power steering pump....hmmmm...).
I figure for under 5 grand I will have a new engine, new transmission, and rebuilt transfer case. I couldn't buy another decent 6.5L rig for that money, and it would barely be a down payment on a new truck.....
Casey
If the power steering pump has that many miles on it, I'd replace the front shaft seal. Mine went bad around 200 thousand. You'll need a special puller to get the pulley off. Autozone has them.
trbankii
09-01-2021, 11:36
I figure for under 5 grand I will have a new engine, new transmission, and rebuilt transfer case. I couldn't buy another decent 6.5L rig for that money, and it would barely be a down payment on a new truck.....
That's how I feel about working on my "ancient" vehicles - what I spend in a year on maintenance and repairs would barely cover a month or two of a new car payment.
Once the lockup clutch starts to slip it will eventually eat up the turbine cover and that fills the tranny full of metal.
The valve body in the 4L80 are aluminum and do not deal with metal debris well at all.
Good time to gitterdone.....
arveetek
10-04-2021, 11:48
I have had very little time to work on the ol' Tahoe recently. However, I have amassed a pile of parts, and was finally able to make a start on reassembly this weekend.
This is where I'm currently at:
https://live.staticflickr.com/65535/51549707027_e272791d14_b.jpg
https://live.staticflickr.com/65535/51550744008_9f3f92606b_b.jpg
https://live.staticflickr.com/65535/51550509731_783d25a2fb_b.jpg
https://live.staticflickr.com/65535/51551223454_b293da6548_b.jpg
The block has been completely cleaned, the cylinders honed, the head bolts chased with a tap, and I got the crankshaft dropped back in with all the clearances checked and caps properly torqued. I am now ready to move on towards putting new rings on the pistons and dropping them in.
The heads are back from the shop with a clean surface and clean bill of health:
https://live.staticflickr.com/65535/51550787188_bf73e04ce3_b.jpg
https://live.staticflickr.com/65535/51551460335_dd6ca411bf_b.jpg
And the transmission and transfer case are back from the shop and ready to drop in:
https://live.staticflickr.com/65535/51549750932_050bc3a055_b.jpg
https://live.staticflickr.com/65535/51551265994_5d6ca8088e_b.jpg
It's nice to see some actual progress after being down for over 2 months.
Casey
DmaxMaverick
10-04-2021, 13:35
Looking good! Slow progress is still progress. Rarely does anything move at a pace we'd prefer. In any case, I'd rather be slow than wrong.
Looks great.
Once you get rolling it will move pretty fast.....
arveetek
10-11-2021, 09:30
I made some more progress on the 'ol Tahoe this weekend. I was able to finish checking all the ring end gaps, got the pistons installed, checked all the rod bearing clearances, installed the timing chain, and got the heads torqued down:
https://live.staticflickr.com/65535/51576413307_2728a36117_b.jpg
https://live.staticflickr.com/65535/51577458743_047d43f429_b.jpg
I then took a few minutes to mock up my "new" HX35 turbo to see what all needs to be done. Looks like I all need to do is cut off a small portion of the upper intake inlet piping, and she should bolt up! Then I need to rig up a bracket to install the proper TurboMaster wastegate controller:
https://live.staticflickr.com/65535/51576413447_ca69454637_b.jpg
https://live.staticflickr.com/65535/51577905719_d7723632b6_b.jpg
https://live.staticflickr.com/65535/51577458898_35380646ee_b.jpg
I found a local guy on FB Marketplace who had a PT Wiring Solutions HX35 exhaust outlet adapter he didn't need, so I grabbed it and it will make this turbo swap pretty painless and hookup to my existing downpipe.
She's coming along, but unfortunately I won't have much time over the next 3 weeks to work on her! :(
Casey
DieselDavy
10-14-2021, 16:58
Sure looks like you are "gettin her done" now! Good Luck Casey!
trbankii
10-20-2021, 04:03
Good to see it coming together!
More Power
10-21-2021, 08:11
I found a local guy on FB Marketplace who had a PT Wiring Solutions HX35 exhaust outlet adapter he didn't need, so I grabbed it and it will make this turbo swap pretty painless and hookup to my existing downpipe.
What's interesting is that Bruce Kirkendall (PT Wiring Solutions) became a subscribing member here in May 2012 shortly after we published a great 6.5 turbo related article (that showed how to install a Holset turbo on the 6.5 along with a lot of technical data on the 6.5 and turbochargers in general). He then inquired about advertising. I responded that I'd work with him to make it work. I didn't hear from him again. I'm disappointed that he doesn't acknowledge The Diesel Page. His Holset turbo parts look just like those we discussed in an article in March 2012.
More Power
10-26-2021, 10:18
...clip
I also came across this in my GM service manual:
I know that resurfacing can be done (I've done it with success on my old 6.2L), but would I be wise to get the .010 thicker gasket from Felpro to make up for the milling on the heads?
Casey
The thicker gaskets are more for when decking the block. A good engine shop will reset the valve seat depth and valve stem length when resurfacing the heads. This was done on the Blazer's heads a few months ago, even though the deck surfaces weren't touched (did the seats, adjusted valve stem lengths).
arveetek
11-01-2021, 12:25
I haven't had much time to work on her (as usual), but I am making progress.
I installed the new oil pump and reinstalled the oil pan. I also replaced the plastic buttons on the rocker assemblies, installed the pushrods and rocker assemblies, and then decided to prime the complete oil system while the engine was still on the stand.
First, I made a bypass hose to make a circuit on the oil cooler ports:
https://live.staticflickr.com/65535/51647353026_864cd9cefd_b.jpg
Then I followed Robyn's advice in previous posts to make a manual oil pump drive using a spare pump drive. I ground the teeth off the drive, removed the cap off the top of the drive, and then welded a nut to the drive shaft:
https://live.staticflickr.com/65535/51646521947_ace83a5333_b.jpg
This allowed me to use a drill to drive the oil pump and create oil pressure through the whole engine:
https://live.staticflickr.com/65535/51647568683_ea0b06e41e_b.jpg
This worked great, allowing me to fully pressurize the oiling system, and to circulate oil throughout the whole engine. It took several minutes of pumping, but I finally got oil to all the rockers:
https://live.staticflickr.com/65535/51648007749_ee5575a3ff_b.jpg
I then sealed the valve covers on. This is the most recent pic I have, before the oiling and before the valve covers went on:
https://live.staticflickr.com/65535/51648007799_90c2757c97_b.jpg
I felt a lot better about checking the oil system before getting the engine installed in the vehicle. Plus, it was a whole lot easier to prime this way! The only drawback is that the pump drive leaks quite a bit of oil up through the top of the shaft and out onto the top of the engine. I ended up making a little funnel to divert the oil away and keep things cleaned up while I primed the system.
Next up is to install the new injectors and reinstall the injection lines; then the engine will be nearly ready to drop back in. I need to powerwash the engine bay and install some new motor mounts, set the transmission and transfer case back in the framerails, and then I should be ready to set the engine in.
Casey
arveetek
11-05-2021, 11:41
Getting closer!
https://live.staticflickr.com/65535/51655490664_a019f17068_b.jpg
I have all the injectors installed, and have started cleaning and installing the old injection lines. Slowly but surely.....
Casey
Looking great.....
Wont be long now..
trbankii
11-07-2021, 16:53
Looking good!
More Power
11-08-2021, 15:48
Getting closer!
I have all the injectors installed, and have started cleaning and installing the old injection lines. Slowly but surely.....
Casey
Looks great! Looks familiar.... ;)
It'll feel good getting it bolted in. I installed the starter & heat shield and right-angle oil filter assy while it was on the engine stand. There's no negative I can think of for doing it. Just be a little careful.
It appears the transmission lines clip is missing on your oil pan rail. It goes under the 2nd (or maybe 3rd) bolt from the front on the passenger side. I also installed the exhaust manifolds on both sides before it went in.
I tweaked by back on Saturday, so I haven't begun the injector install yet in daughter's Blazer. :(
Jim
arveetek
11-09-2021, 06:36
Looks great! Looks familiar.... ;)
It appears the transmission lines clip is missing on your oil pan rail. It goes under the 2nd (or maybe 3rd) bolt from the front on the passenger side. I also installed the exhaust manifolds on both sides before it went in.
Ah yes, I forgot about the lines clip, thanks for pointing that out!
Casey
More Power
11-09-2021, 09:05
Ah yes, I forgot about the lines clip, thanks for pointing that out!
Casey
I noticed the missing trans cooling lines clip only because I pondered where mine went for quite a while... I didn't know where the clip went till I got that spare engine a while back. Luckily, it still had the clip on the pan rail.
There are two support rods that bolt onto the trans bellhousing cover and extend forward. The longest one mounts to the starter side of the engine and bolts onto a bracket on the block side of the passenger side motor mount. The shorter rod... I don't know what/where the forward end bolts to. :confused:
Oh, and I recommend you not have the Oil Pressure Switch installed till after the engine is in... The OPS is fragile.
Yukon6.2
11-09-2021, 09:43
I have seen a plate between the motor mount and the block for the rods to attach too.
It's just a flat plate that extends past the mount with a hole in it.
arveetek
11-09-2021, 09:50
There are two support rods that bolt onto the trans bellhousing cover and extend forward. The longest one mounts to the starter side of the engine and bolts onto a bracket on the block side of the passenger side motor mount. The shorter rod... I don't know what/where the forward end bolts to. :confused:
I only had the one longer rod on the passenger side when I pulled my engine....
Casey
The IFS front ends only use one rod.....Diffy is in the way of the other one....
arveetek
11-15-2021, 15:54
Making progress!
Rebuilt transmission and transfer case installed:
https://live.staticflickr.com/65535/51683324219_0a3c4e911c_b.jpg
And then my helper (my 11 year old son) and I worked on getting the engine stabbed back in:
https://live.staticflickr.com/65535/51682914628_8071e5a1a5_b.jpg
https://live.staticflickr.com/65535/51682914583_ca7aa42801_b.jpg
Success!
https://live.staticflickr.com/65535/51682914543_980520d72b_b.jpg
https://live.staticflickr.com/65535/51682655006_9e1c7bae69_b.jpg
My son was a great help; he operated the engine hoist and the floor jack while I was underneath lining everything up. He's an awesome worker.
Won't be too much longer now.
Casey
Looking great.....Having that extra pair of hands is such a big help...
More Power
11-15-2021, 19:01
Looking good, and you're so close! It's great that your son is taking an interest.
I like that you removed the passenger side wheel well liner. That'll make getting the electrical and the turbo installed easier. Looks cold outside your garage! Was 67 degrees here today, but that won't last long. ;)
arveetek
11-15-2021, 19:52
Looking good, and you're so close! It's great that your son is taking an interest.
I like that you removed the passenger side wheel well liner. That'll make getting the electrical and the turbo installed easier. Looks cold outside your garage! Was 67 degrees here today, but that won't last long. ;)
I'm so grateful to have a son who loves all things mechanical! He'd rather be outside or working in the shop than be stuck inside watching TV.
Removing the inner fender makes life so much easier - whether it's replacing glow plugs, working on the turbo, or working on the exhaust, it's a no-brainer for me. I can literally have the fender out in less than 10 minutes.
It was chilly this weekend in SW Missouri. Lows in the upper 20's and highs in the upper 40's. It was 65 today and will be 70 tomorrow. The temps have been a roller coaster for about 2 weeks now. But mostly what you're seeing are dirty windows! :D
Casey
arveetek
11-17-2021, 12:56
Of all the parts I had to order for this project, one of the items that I am most excited about is a brand-new, aftermarket replacement wire harness for the injection pump circuit:
https://live.staticflickr.com/65535/51687563379_4e1bc932a2_b.jpg
The original harness was in awful shape. After 26 years and nearly 380K miles, the plastic connectors had become brittle and were breaking apart:
https://live.staticflickr.com/65535/51686879686_86169167cb_b.jpg
https://live.staticflickr.com/65535/51686879636_7cb167165d_b.jpg
A completely rebuilt engine will do me no good if the wiring harness that controls the fuel delivery system is worn out. I feel this will provide a lot of trouble-free service in the coming years:
https://live.staticflickr.com/65535/51686879656_014d01d904_b.jpg
https://live.staticflickr.com/65535/51687157508_4da3358321_b.jpg
https://live.staticflickr.com/65535/51686879601_68931c03d7_b.jpg
https://live.staticflickr.com/65535/51687157588_6aaab76cc7_b.jpg
I'm very pleased with the fit and finish of this harness.
Casey
a5150nut
11-17-2021, 19:23
Do yourself a favor and get a can of spay tuner cleaner with oil or us some dielectric grease when you assemble those'
More Power
11-18-2021, 13:16
That new harness looks nice! Where'd you get it?
I had a couple of take-off IP harnesses that I got from Peninsular back in the late 1990s. I didn't need to use them with my 6.5 project, but they are a great resource considering the dwindling supply, and a great backup. Luckily, all of the Blazer's original harness connectors were in pretty good shape.
And, I agree with A5150 about the electrical cleaner/lube. I bought a spray can of electrical cleaner and a can of silicone spray from NAPA to allow the connectors to be clean and go together easier. They do get brittle over time.
arveetek
11-18-2021, 16:06
That new harness looks nice! Where'd you get it?
Here:
https://quadstartuning.com/collections/engine-internals/products/6-5l-engine-wiring-harness?variant=41414604242
Casey
arveetek
11-22-2021, 06:55
4:30 pm yesterday (Sunday) afternoon:
https://www.youtube.com/watch?v=mPMMtMAyQmo
After getting the radiator installed and topping off all fluids, I cranked the engine over without the glow plugs in order to circulate the oil and to also help bleed the air out of the fuel injection system. It didn't take long before there was a decent puff of fuel vapor coming from each cylinder.
I then installed the glow plugs without hooking up the wires. I cranked it over again to see how it would turn over under compression, and to my surprise, it acted like it wanted to start! I then hooked up the glow plug circuit wiring, and she fired immediately and then stalled. Just a little more cranking, and she came to life! One of the easiest first starts I've ever had.
Now I just need to install the exhaust down pipe, the inner fender, grille, bumper, hood, and finish up the air cleaner setup, and she'll be ready for a road test.
Casey
Getting that harness is a real plus for sure.
When I did the engine in Dahooooley I was able to find a NOS delco harness off of ebay.
Definitely provides peace of mind....
Looking good..
Very nice Casey! All the hard work is paying off! Can’t wait to see the next video of you driving it! :-)
More Power
11-22-2021, 17:15
4:30 pm yesterday (Sunday) afternoon:
https://www.youtube.com/watch?v=mPMMtMAyQmo
After getting the radiator installed and topping off all fluids, I cranked the engine over without the glow plugs in order to circulate the oil and to also help bleed the air out of the fuel injection system. It didn't take long before there was a decent puff of fuel vapor coming from each cylinder.
I then installed the glow plugs without hooking up the wires. I cranked it over again to see how it would turn over under compression, and to my surprise, it acted like it wanted to start! I then hooked up the glow plug circuit wiring, and she fired immediately and then stalled. Just a little more cranking, and she came to life! One of the easiest first starts I've ever had.
Now I just need to install the exhaust down pipe, the inner fender, grille, bumper, hood, and finish up the air cleaner setup, and she'll be ready for a road test.
Casey
Great job! The enthusiasm from your son is priceless. The engine sounds great.
It's always with a little trepidation that I look beneath the vehicle for leaks and such... ;)
arveetek
11-23-2021, 07:20
Thanks guys!
I got it on the road about 9 pm last night, and drove it to work this morning. I'm still a bit nervous, but everything seems to be working well. I accidentally overfilled the transmission, so it's burping a bit of fluid out, but other than that, so far so good!
And holy cow, that new turbo is crazy! Driving without the hood on last night the turbo whine was almost obnoxious! With the hood on it's much quieter, but I can still hear the turbo the whole time I'm driving. Very nice! I've already gotten it to 15 psi with little effort. The old GM-4 maxed out at 13 psi under heavy load.
More updates soon!
Casey
Any chance you could hook up a compression tester and take it on a drive to see what your compression is at 15psi with the Hx35w? I am very curious to see those numbers.
More Power
11-23-2021, 14:45
Any chance you could hook up a compression tester and take it on a drive to see what your compression is at 15psi with the Hx35w? I am very curious to see those numbers.
Combustion pressure will wreck a compression tester.
Great job.....
Worth the time and effort for sure....
arveetek
11-24-2021, 08:06
The engine is running great, but it appears my transmission guy supplied me with the wrong torque converter. It appears I received a TC for a gasoline application; my stall speed is around 2500 RPM! I noticed during my initial test drive that it seemed to take a lot of throttle and RPM to get moving. I first attributed it to the fact that I hadn't driven the vehicle in 4 months, and had gotten used to driving a little Volvo wagon and forgotten what it was like to drive my diesel. However, I finally realized I had a much higher stall speed than before.
There seems to be some confusion on torque converters for the 4L80E... most parts catalogs list the same part number for both gas and diesel versions. However, I did finally find a parts listing that showed low stall and high stall options. The low stall is 1600-1800 for diesels and big blocks and the high stall is 2200-2400 rpm for everything else.
My transmission guy is willing to replace the torque converter. My question: can anyone recommend a good, high-quality performance low-stall torque converter? If I'm going to have to pull the tranny again, might as well do it right once and for all.
I'm wishing now I had pressed this issue further, but I trusted my transmission guy. He's done great work for me in the past, and specializes in GM racing transmissions. But, I don't think he's had too many diesel transmissions come through his shop.
Casey
Guy likely grabbed a converter for a 3/4 ton with a 5.7 gasser.
That is not a good thing.
Buttttttttttttttt....you can yank the Tranny and T case back out and down....The swap in the correct one.
A pain in the butt after all the work.....
If you don't pull heavy with it....It should be OK....JUST GOING TO RUN A BIT DIFFERENT.
Where does the lockup clutch apply ???
Should be at about 45-50 MPH AT MODERATE/LIGHT THROTTLE
arveetek
11-24-2021, 09:02
Lock up occurs where it did before, about 55 mph; this is with 3.42 gears and 33" tires, so it's a bit higher lockup speed than stock due to the oversized tires. However, there is about a 500 to 600 rpm difference when locked up, which is much more than before.
I pull my 21' camper, so the high lockup will be quite annoying when it's not locked up; probably will hurt the MPG department as well.
I see Transtar makes an upgraded TC for the diesel for a decent price. I'll see if my tranny guy will order that for me.
To his defense, I looked up where he sourced his converter, and they only list one converter for both gas and diesel. I'm not sure why that it is, but if you go to Rock Auto, they also show the same thing....
I spent so much time and effort focused on the engine building, I slipped up and assumed my transmission guy would put in the same kind of effort.
Casey
Monster Transmission is good too
I always use a local tranny converter rebuilder.
If you are using this rig to tow...Get a converter that has the low stall, welded or brazed blades in pump and the turbine.
Be sure to get a heavy service lockup clutch.
For the amount of work involved...stay away from the parts houses and online stores.
Go to a reputable converter rebuilder and spec out what you want.
The better than lockup clutch...the longer they live....
These things get the rat crap beat out of them......
Any other performance upgrades...such as better torrington thrust bearings and such...do it.
The stock spec stuff that most online stores sell are "Sort of a stock part" IF YOU ARE LUCKY..
Monster offers some good things.
Call them up and tell them what you have.
Rig
Engine
Tranny
Butt gears
AND WHAT YOU DO WITH IT.
These guys offer a 1300-1600 stall HD converter.
They may have something better too..
Again...A HD lockup clutch if they have it.....GOOD IDEA
Any pics of the motor in your motor bay?
a5150nut
11-26-2021, 13:14
Any pics of the motor in your motor bay?
Scroll back one page there are some there.
Scroll back one page there are some there.
Sorry, should have been more specific.
Pics of the turbo, intake, turbo master mounting and air box? Full completed pics
arveetek
11-27-2021, 19:52
Sorry, should have been more specific.
Pics of the turbo, intake, turbo master mounting and air box? Full completed pics
My air cleaner setup is temporary, I want to build a true cold-air intake system eventually. For now, I ordered some 4" silicone elbows and a K&N filter to get me going:
https://live.staticflickr.com/65535/51708600507_52a3e84664_b.jpg
https://live.staticflickr.com/65535/51708600537_dc306e29c6_b.jpg
https://live.staticflickr.com/65535/51708600487_8618de68d8_b.jpg
I had to build a bracket for the TurboMaster and mounted it to the turbo flange:
https://live.staticflickr.com/65535/51708613957_50eb7acd1a_b.jpg
https://live.staticflickr.com/65535/51708613972_3e99a169b8_b.jpg
https://live.staticflickr.com/65535/51708600477_57953f3618_b.jpg
Today I installed a turbo blanket, since I couldn't reuse the original heat shield:
https://live.staticflickr.com/65535/51710064564_ded4120291_b.jpg
https://live.staticflickr.com/65535/51709663468_2e520da9a4_b.jpg
She's been running great all week and no issues with the engine. She starts great with little smoke, and cold starts in the mid 20's seem to be no effort. I've never had a 6.2L/6.5L (and I've had several) start this easy.
Video of the quick starting:
https://www.youtube.com/watch?v=RApRxTOmO90
I'm looking forward to getting the correct torque converter so she will drive easier. Right now it reminds me of a dump truck with an old Allison where you have to mash the throttle and wait for stuff to start moving. It's great for spooling the turbo and hearing the whistle, though! :D
Casey
Can you tell me where you got that turbine housing blanket? Mine's worn out.
Thank you for the motor porn. Looks very nice! Have you considered to run a snorkel of some sort to get a true cold/ram air intake? Perhaps an inner cooler for the 7+boost as Jim suggests? What kind of covering is that over the fuel filter and A/C Dryer? The dual gauges on the fuel filter housing is dope! X2 on the turbo blanket! Where did u order that from?
There is a inline air filter box with a 5” OD that might fit on the Hx35w intake elbow that could help achieve cold air.
https://www.summitracing.com/parts/spe-9832?rrec=true
arveetek
11-28-2021, 14:22
Turbo shield:
https://quadstartuning.com/collections/turbochargers-parts/products/lava-shield-turbo-blanket
All sorts of cool heat shielding products direct from the manufacturer:
https://www.heatshieldproducts.com/automotive/turbo-heat-shields
The A/C dryer cover is factory original. The fuel filter cover is of my own design; it's actually a 12V heater; it's original use was for keeping drain pipes from freezing on RV's; it's a peel-and-stick heat pad that I stuck to a piece of sheet metal that is held on to the filter with a hose clamp. The aftermarket Racor filter housing I'm using did not come with any sort of fuel heater, so I came up with this one.
I would like to go with an intercooler some day. One step at a time!
Casey
Turbo shield:
https://quadstartuning.com/collectio...-turbo-blanket
Thanks.
More Power
11-29-2021, 16:33
Lock up occurs where it did before, about 55 mph; this is with 3.42 gears and 33" tires, so it's a bit higher lockup speed than stock due to the oversized tires. However, there is about a 500 to 600 rpm difference when locked up, which is much more than before.
I pull my 21' camper, so the high lockup will be quite annoying when it's not locked up; probably will hurt the MPG department as well.
I see Transtar makes an upgraded TC for the diesel for a decent price. I'll see if my tranny guy will order that for me.
To his defense, I looked up where he sourced his converter, and they only list one converter for both gas and diesel. I'm not sure why that it is, but if you go to Rock Auto, they also show the same thing....
I spent so much time and effort focused on the engine building, I slipped up and assumed my transmission guy would put in the same kind of effort.
Casey
I love 3.42 gears in a 6.2/6.5 - if the vehicle isn't used to tow heavy.
I think 55-60 mph is likely where the TC should lock in OD with 3.42 diff gears. Locking sooner would be too low of an RPM, which puts more of the torque impulses into the transmission/driveline. Lil Red with its Duramax/Allison and 3.42 gears also locks the torque converter 55-60. I think we did a story once about a BD 4L80 TC manual/auto lock controller. Have to check the table of contents in the 6.5 books.
Casey, I have another question for you. I am not to familiar with Tahoe’s, but I was wondering if you had an RPM gauge and if so, what RPM were you at when you got to 15psi boost?
DmaxMaverick
11-30-2021, 14:21
All production model civilian 6.5TD's have a tach in the IPC, driven by the alternator.
arveetek
11-30-2021, 20:01
Casey, I have another question for you. I am not to familiar with Tahoe’s, but I was wondering if you had an RPM gauge and if so, what RPM were you at when you got to 15psi boost?
It was fairly short lived, but I believe it was around 2800 rpm in 3rd gear locked, somewhere around 70 mph.
Casey
arveetek
12-10-2021, 07:34
As of 9 pm last night, this is the current status of the ol' Tahoe:
https://live.staticflickr.com/65535/51738199595_bb72e3b71b_b.jpg
https://live.staticflickr.com/65535/51736487587_017c5c1489_b.jpg
With only 931 miles on the engine, Tuesday night she suddenly lost power, developed a knock, started missing, and blowing a ton of smoke out the exhaust. The smoke was white, unburned fuel. I was hoping it was just a failed injector. By cracking one line at a time with the engine running, I narrowed the problem down to cylinder 4. Naturally, the cylinder with the problem is the hardest one to access, right behind the turbo.
Video of engine knocking and missing. (https://www.youtube.com/watch?v=bLFsMIXodvw)
I ended up removing the turbo to gain better access to the cylinder. I pulled the injector, but there was nothing visibly wrong. I swapped in one of my original injectors, but there was no change. I then had my son crank the engine over with the glow plug removed (and the fuel system deactivated so it wouldn't start), and that's when I realized there is no compression on cylinder 4! I can keep my thumb over the glow plug hole with the engine cranking over, and can only feel a slight puff.
I removed the valve cover to make sure everything was okay in the valve train, thinking there might be a valve stuck open, a bent pushrod, or something of that sort, but everything is normal in the valve train.
So after 4 months and thousands of dollars, I'm essentially right back where I started. I still need to swap out the torque converter, so it looks like pulling the engine (again) is in my future.
I'm nearly sick to my stomach at this point and really discouraged. I can't imagine what went wrong, or what I missed. I did everything by the book to the best of my ability.
Casey
Wow, that sucks...
Can you blow air into #4 and see where it's leaking out? Maybe a failed exhaust valve...
Yukon6.2
12-10-2021, 09:24
That sucks Casey
Had that sinking feeling once or twice in the past as well.
Hopefully after coffee and a night of sleep,you will in a better state and tie back into it to solve the issue.
Try to remember all the trouble free miles you enjoyed in the Tahoe.
Take Care
DmaxMaverick
12-10-2021, 11:20
Wow, that sucks...
Can you blow air into #4 and see where it's leaking out? Maybe a failed exhaust valve...
This.
It may not be that bad. Maybe a gasket or valve/seat. Think positive, for what it's worth.
arveetek
12-10-2021, 13:32
This.
It may not be that bad. Maybe a gasket or valve/seat. Think positive, for what it's worth.
I suspect it might be a broken valve. Very similar symptoms to when I pulled this particular 506 engine out of the donor truck in the first place. If you recall, cylinder 1 had a busted exhaust valve and a piston that was banged up. I theorized that the engine had ingested a glow plug and caused the valve to break. Now I'm wondering if there are some hidden flaws in the valves themselves, or perhaps the valves got too hot and became brittle for some reason? Perhaps the original valve failed on its own without a foreign object. If so, I'm going to need to go through and replace all the valves to be sure. But that's just a theory at the moment; could be a broken piston as well. I'll have to pull the head to find out.
It may not be that bad, but it means a lot more work, again. I'm just really tired and don't feel like going through all this again. I still need to replace the torque converter (which just came in today... what timing), so I might as well pull the engine and see what's really going on and replace the torque converter while its out. I just don't want to do all of that again.
Casey
Gods speed....Sorry to hear of the failure.....
Most of us have been down this road a time or two...
Hope it is an easy fix.
I just listened to the video.
My bet is this is a valve issue.... or valve spring
A very common failure after a rebuild is lifter failure. The smallest amount of contaminates can and will cause lifters to seize or collapse. Such a cheap $12 part can cause such havoc. I heard your video with my eyes closed and recalled the same exhaust sound during one of my fun filled lifter failure adventures.
Is there any up and down movement on any of the rocker arms. If not, turn the crank 1/2 turn and check for play again to confirm it is not lifter failure.
If it is lifter failure, some lifters can be pulled easily without removing the head. The outer cylinder lifters are a pita if not impossible without the right tools.
Was there a kind of thumping noise coming from the intake?
There is the possibility that a cylinder got a crack in it. If you are willing to pull the pan and check for cracks into that cylinder, would help determine if that motor is garbage.
Possible the head gasket took a poop. Too.
Did you check for air bubbles or oil in the radiator? Check oil color?
Do not get discouraged! I know exactly how you feel! Spending thousands of dollars and countless hours on a motor only to find out it is **** once it is installed…
This very reason is why I sold all my motors and parts for $15,000 and simply bought an Optimizer with a warranty.
Good luck man! Keep us posted!
arveetek
12-11-2021, 08:05
I already pulled the valve cover and checked the valve train; valves are opening and closing normally.
No air or oil in cooling system; no coolant in the oil.
I'll bet a valve broke.
Casey
Yukon6.2
12-11-2021, 08:47
Not that it makes any difference...
If a valve broke right off the valve spring should/could be higher then it's partner.
Well, you are already 1/2 there… I would pull just the head not the whole motor and check it out. You could be rolling again by tomorrow! Giterdun!
arveetek
12-11-2021, 09:42
Not that it makes any difference...
If a valve broke right off the valve spring should/could be higher then it's partner.
When I disassembled this motor to start with, it had a broken exhaust valve - about 1/2 the outer edge was missing, but most of the valve was still intact, and it still opened and closed normally, but would not allow the cylinder to hold compression. At the time, I thought the engine had ingested a glow plug and damaged the valve, but now I'm wondering if the valves were brittle for some reason.
Here's the original broken exhaust valve:
https://live.staticflickr.com/65535/51394387504_7dfa4447ef_b.jpg
I'm suspecting I will find something like this when I pull the head. If so, both heads are coming back off and all new valves are going in.
Casey
DmaxMaverick
12-11-2021, 10:45
Turn the crank to TDC and put some air in the cylinder. You need to find where the leak is. This is free, and takes a few minutes for a priceless revelation.
I agree with Maverick......
The valve may not have lost enough pieces to damage the piston...and the part flew out the pipe..
I seem to remember reading that the valve have a hard face overlay (Two piece)
Your piccy clearly shows this.
The hard face portion broke and fell off.......
NEW VALVES FOR SURE.....
DmaxMaverick
12-11-2021, 12:01
OEM valves are induction hardened since about 1980. They may be bi-metal, but still induction hardened. Who knows with aftermarket, though. The pictured valve looks like it parted at the hardened, bi-metal depth. A single failure can happen at any time, for any number of reasons, and it can be addressed on an individual repair. Multiple failures should change that approach. Any valve from the same lot would be suspect, so replacing the set would be right. A good, used OEM set would be as good, or better, than most aftermarket, in my experience.
The stuff from across the pond ....not so much.
DmaxMaverick
12-11-2021, 12:46
The stuff from across the pond ....not so much.
No doubt. Even Clearwater complete heads use recycled valves, rather than sourcing them from the source of the heads, which may be cheaper. What concerns me is the foreign clones. It can be difficult to know if you have OEM, or an OEM clone from who knows where. Used valves, as well as many other parts, are a crap-shoot because of this. It's best to buy them from a known-good source, who sources true OEM or good, US quality aftermarket parts. There's a lot of good stuff out there, but there's also enough junk to mess the lot (bad apples).
arveetek
12-11-2021, 13:08
I still have the valves from my original 1995 heads that (as far as I know) are the original, GM installed valves. Assuming I will need to replace all the valves, should I try to use those? They were functioning fine; just had 376K miles on them.
Still a lot of assumptions at this point, but if it is another broken valve, my plan was to take the heads back to the machine shop and have all new valves fitted; perhaps I would be better off to simply lap the 1995 valves and install them in the 1997 heads and reuse all the new seals that were recently replaced...
Really, before I get too far ahead of myself, I need to finish my diagnostics. It might be a couple of days before I have time to get back out to the shop, though.
Casey
Ya know....
You need to swap the converter out anyway...
If it were me, I would rip the hood off...yank the engine out and get it on the stand....
Far easier to work on that way too...
Rip both heads off and gitterdone....
Spending time fooling around trying to nail it down is pretty much a moot point......
It has a dead hole.....Ya need to swap the converter anyway.....
The engine is easy to yank out.....Far easier to work on the heads out on the stand too....
Just my 2 cents worth.
arveetek
12-11-2021, 13:42
Ya know....
You need to swap the converter out anyway...
If it were me, I would rip the hood off...yank the engine out and get it on the stand....
Far easier to work on that way too...
Rip both heads off and gitterdone....
Spending time fooling around trying to nail it down is pretty much a moot point......
It has a dead hole.....Ya need to swap the converter anyway.....
The engine is easy to yank out.....Far easier to work on the heads out on the stand too....
Just my 2 cents worth.
Pretty much what I had planned on doing!! :D
Casey
Small block heads are not bad in the chassis.....These suckers are just too heavy.
Out on the floor you can get right after it and gitterdone without wrecking your back jumping the heads....
Plus you can clean the decks easily and be sure everything is spiffy going back.
The used valves from the 95 heads....I would not be opposed to using them.
Grind them and lap them to the seats in the fresh heads....
The only Caveat might be any damage to the one head.....LETS HOPE IT IS NOT HURT......
Do you have std pistons ????
IF you wind up and need a piston....I think I have some std size ones on the shelf.
If ya need one....let me know...Getcha one in the mail....They need a new home...
trbankii
12-12-2021, 09:45
Hang in there. I know how horrible that can be - the good feeling of getting a job done and then things go south again.
I feel for you.
More Power
12-12-2021, 15:26
As of 9 pm last night, this is the current status of the ol' Tahoe:
...clip...
So after 4 months and thousands of dollars, I'm essentially right back where I started. I still need to swap out the torque converter, so it looks like pulling the engine (again) is in my future.
I'm nearly sick to my stomach at this point and really discouraged. I can't imagine what went wrong, or what I missed. I did everything by the book to the best of my ability.
Casey
Bummer Casey.... Sorry this happened. :(
I don't have any exhaust valves. But they aren't that expensive. I think the engine shop charged me about $20 for a replacement a few months ago. That may be all you'll need. I know that in the early 1990s I had a local diesel shop install new head gaskets in my first 6.2L diesel pickup. I was called in when they got the heads off, and was shown the top of one piston that had been beat up by a loose glow plug tip at some point in its history (happened before I got the truck). We chose to ignore it. A couple years later we did a full rebuild - unrelated to the piston crown.
I have images somewhere in the archive of a valve failure just like the one your engine developed. The material GM used for the exhaust valves is an alloy called "Stellite", which is likely some alloy of stainless (resistant to heat). You can read more about the alloy here: stellite alloy steel exhaust valves (https://duckduckgo.com/?q=stellite+alloy+steel+exhaust+valves&ia=web)
I mentioned to my daughter the possibility of a problem developing with the engine even before we attempted the first start. It's the nature of the beast. I wanted her to be prepared, and we even talked about a way(s) forward if that happened. So many things have be right for success, let alone avoiding a lurking wild card like the valve problem.
The original lifters used in our 6.5 Blazer had been laying horizontal on towels for 12 years. I considered new lifters when put back together this summer, but I didn't want to chance getting cheap imports. I thought the 187K mile GM originals were a better gamble. They were all cleaned and checked before going in. The only thing I didn't do that I should have was pump them up using 10W oil or ATF before installation. I suspect it took some seconds of running to accomplish the same thing. BTW - our 6.5TD Power Project engine got its original lifters when we rebuilt it... It ran another 300k before I sold it - still running great... Jim
Casey
I have been down this road myself....
It is disheartening for sure.....
You have valves from the 95 engine to rob for parts....A good thing.
A set of head gaskets and bolts are the big items (A known quantity)
Take a deep breath....let it out slow and if the personal need is there....A few expletives are certainly understandable....
I am pretty sure that you did not miss anything......It is real tough to catch the sort of stuff you are dealing with unless you just SPEND $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ and replace everything.....still.....CHIT HAPPENS.
Ask the Boys that were running Chernobyl how it feels when your parts fail....OMG
Get the engine out.....Get the RH side head off and see wassssssup....
Stop beating yourself up.....This sort of thing happens....especially when you are trying to keep things on a tight budget....
Gods speed......EVERYTHING WILL BE FINE.....AND IF ITS NOT FINE....IT'S NOT EVERYTHING :D
arveetek
12-13-2021, 06:49
Thanks for the kind words and encouragements everyone!
Robyn, yes this engine has std pistons. I still have my original 95 engine for parts, so I'm good there. In fact, I already swapped in one piston from the 95 to replace the banged up piston in cylinder one. Thanks for the offer though, I appreciate it.
I haven't had a chance to touch it all weekend; in fact, the way things are going, I may not be able to get to it until this coming Saturday. I'll keep you updated on what I find out.
Casey
arveetek
12-20-2021, 13:16
Finally had time to work on the ol' Tahoe this weekend. Took off Friday to get a head start, and by the end of the day Friday, she looked like this (again):
https://live.staticflickr.com/65535/51759386901_10f523c7a1_b.jpg
https://live.staticflickr.com/65535/51759627478_5ea5c85f98_b.jpg
After pulling the passenger side head, my suspicions were verified: the exhaust valve broke in the exact same manner as it had on cylinder 1:
https://live.staticflickr.com/65535/51759627458_e0e5e8a414_b.jpg
I found the exact same damage as before in cylinder 1; bits of the valve had imbedded into the top of the piston and banged it up pretty badly, along with the head. There was also some slight scoring on the cylinder wall:
https://live.staticflickr.com/65535/51760036979_fcd1ed3615_b.jpg
https://live.staticflickr.com/65535/51759627433_b677d8c44e_b.jpg
https://live.staticflickr.com/65535/51758554967_8d85a7f827_b.jpg
https://live.staticflickr.com/65535/51758554962_9d6d5e5746_b.jpg
https://live.staticflickr.com/65535/51759386821_f9eae9be44_b.jpg
When I first disassembled this engine (if you recall, this is my spare 1997 506 block, not my original 1995 929 block), I assumed it had ingested a glow plug and that is what caused this damage. Apparently, that is not the case. For some reason, the exhaust valves are self-destructing on their own.
I have both heads and off and will be dropping them off at the machine shop tomorrow morning to have all new valves installed.
I spent quite some time honing the damaged cylinder yesterday afternoon; looks like it will clean up okay. I already have a good piston pulled from my original 1995 engine to swap in.
Casey
At least we know what happened.....
Strange things as to why the valves are going away like that......?????
Looks like the short block is still fine.
Just a thought here.......Look at the cost of the repairs on these GM heads....then take a good look at a set of Fresh AMG 6.5 heads.
New BETTER castings, new valves, new springs....ZERO time on them.
I used a set of AMG heads on the Dahoooooley when I did the engine...Those are lovely heads.
Just swap your Rockers and push rods.....
The new AMG heads are gonna be a tad more $$$$ but used heads on a 6.5 is a time bomb IMHO
If you decide to go with AMG heads...be sure to specify PICKUP/SUV heads...The P400 for the Hummer/Van use different intake bolt angle...and will not work with pickup/suv intake manifolds.
This mistake is how I ended up with a set of the P400 heads...
arveetek
12-21-2021, 09:37
The new AMG heads are gonna be a tad more $$$$......
I would love to, but I've already blown a huge wad on this project and can't justify spending that much more. Other than the valves, these heads are actually in really good shape, and crack-free.
I decided to go ahead and replace the lifters while I'm at it, though. I was staring at the lifters with the heads off, and thought, "I better replace those too while it's easy to do." I don't want to take any more chances at this point.
Casey
Copy..
I understand fully.........If the one head is not hurt....should be OK
More Power
12-22-2021, 10:58
https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=6367&d=1640195529
https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=6368&d=1640195568
Ghost of Christmas past...
Here are a couple of images sent to me in 2013 by member Bob Farley.
In combination with your experience and one or two others I've heard about, are these the result of a bad production run or a change in subcontractor? It's not inherent in the design or this problem would have been epidemic.
Glad you have a plan Casey...
arveetek
12-22-2021, 11:09
https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=6367&d=1640195529
https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=6368&d=1640195568
Ghost of Christmas past...
Here are a couple of images sent to me in 2013 by member Bob Marley.
In combination with your experience and one or two others I've heard about, are these the result of a bad production run or a change in subcontractor? It's not inherent in the design or this problem would have been epidemic.
Glad you have a plan Casey...
Wow! You're right, that's the exact same failure! The only conclusion I can come up with is what you stated: either a bad production run or a change in subcontractor. Probably no way to find out.
My advice to anyone reading this: if you find a valve failed in this manner, go ahead and replace ALL the valves. If one has failed, the others are not far behind.
My machine shop stated that the intake valves would probably not fail in this manner, but I'm not taking any chances. All the valves are being replaced. I hope to have the heads back the first of next week. I am off all next week, so hopefully she'll be back on the road next week!
Casey
Is it possible some valve metal pieces got past the piston rings into the oil?
DmaxMaverick
12-30-2021, 11:18
Is it possible some valve metal pieces got past the piston rings into the oil?
How would that be possible, with piston, rings and cylinder intact? It wouldn't.
How would that be possible, with piston, rings and cylinder intact? It wouldn't.
If there is heavy scoring on the rings, I thought it could be a possibility. I would hate to see Mr Casey have future problems.
arveetek
12-30-2021, 13:50
I didn't see any evidence of metal in the oil. The rings didn't look damaged, either. Only the cylinder wall had one scuff, which I was able to get out with honing. I was tempted to reuse the rings, since they only had 931 miles on them, and I didn't see any visible damage. However, I was able to locate a matching set of rings for one piston, and got them installed.
Swapped in piston from my original 929 engine, and replaced the lifters for good measure. I got the heads back on Tuesday morning. Engine is now repaired and reassembled and my son and I got it dropped back into place this morning. Hope to have it started and running tomorrow.
Casey
DmaxMaverick
12-30-2021, 14:49
If there is heavy scoring on the rings, I thought it could be a possibility. I would hate to see Mr Casey have future problems.
That would suggest broken rings and piston, at least. As Casey said, the cylinder wall damage wasn't bad, and would have to be a lot more than he found. If it were to happen, it would destroy the engine, entirely. A gouge in a cylinder deep enough to pass a chunk of valve past the piston, compression and oil rings would push it beyond recoverable (short of a sleeve, which is not at all practical with this engine). I've seen similar damage in engines ran well beyond time for overhaul, and that was the result. That's one you leave swinging in the tree.
Sounds like you are almost there......
Looking forward to hearing it run.....
arveetek
01-01-2022, 10:10
https://www.youtube.com/watch?v=scr4pe6Lxng
Got her back on the road yesterday around noon time.
The correct torque converter makes driving much nicer, as the engine doesn't have to scream to get moving. However, there is not as much turbo whistle now since the engine RPM remains much lower most of the time.
For the easiest first starts, I followed the recommended procedure: I left the glow plugs out (with the plugs out, there's no compression and therefore little resistance on the starter) and cranked the engine over to build oil pressure, and then continued cranking until fuel mist starting coming out of the cylinders; then I installed all the glow plugs, cranked it over again, and she lit right off! No drama at all when using this procedure, as this naturally bleeds the fuel injection system easily.
Casey
So happy that your rig is back up.
I learned that priming procedure years ago when I fooled with the Old's 5.7 diesels.
After frying a couple starters and draining batteries...GOTTA BE A BETTER WAY.
Yup...yank the plugs and spin it over....
The Turbo does make it a little bit tougher....but still much easier than draining batteries and melting starters...
Also the fuel system does not have to battle compression to get the fuel to shove the air out of the fuel lines.....
Good deal.....
GOTTA BE A GOOD FEELING TO HAVE THE RIG UP AND GOING.....
trbankii
01-02-2022, 13:31
Great news for the New Year! I'm happy to hear it!
arveetek
01-08-2022, 18:14
The Tahoe is still running great, but I do have one small issue: there is a vibration that is engine RPM related that is really annoying me. At first I thought I was being paranoid, but I can definitely tell it's there. I can feel it the most between 1500-2000 rpm, even sitting still in park. It feels a lot like a bad u-joint feels at highway speed, but it's obviously engine related, and it wasn't there before (right after the initial engine rebuild).
Today I decided to verify if it's in the engine or transmission. I unbolted the torque converter from the flexplate and then started the engine; she was smooth as silk (or at least as smooth as a 6.5L diesel can be). I tried several times to replicate the vibration and could not detect it. That relieved my fears that there might have been some sort of slight misfire or other engine issue. I bolted the torque converter up 180 degrees from where it was (just to see if maybe there was some harmonic issue between the TC and flexplate that might be resolved by clocking the TC at a different spot), but the same vibration returned. It appears the new torque converter is out of balance.
It's really not that bad, and a lot of people might not even notice it, but it's driving me up the wall since I know it shouldn't be there. At just the right RPM, I can see the rear view mirror start to shake in rhythm to the vibration.
I have reached out to the torque converter supplier to see what the next step is.
Casey
Torque converter is junk.
I had a batch of junk converters years ago.
What happens is the hub that goes into the tranny was replaced and the damned thing is not concentric.....
Allow to run as it is will tear up the front pump on the tranny and it will also add stress to the crank shaft...
Only one way to fix it....
Get that bad boy out and take it back to the seller.
I had six I believe that were bad.....
I had one that would literally shake the mirrors.
I dragged on out of the rig after doing what you have done....Grabbed it in the lathe by the hub and spun it..
Damned thing wobbled like a button on an outhouse door....
I was running out 1/8" or more..
All manner of hell came loose when I discovered the issue.
The rebuilder tried to convince me that it was a bad vibration damper.
He did not was to do a thing..
I threatened to burn his outfit down.....He finally gave me my money back.....I replaced it with a different brand...also spun the replacement in the lathe first.
Sorry to hear of the issue.
Get that bad boy out of there......
DmaxMaverick
01-08-2022, 18:45
It's great to hear the good news. However, an unbalanced converter is no small thing. Serious damage (and starting all over again, again) can happen as a result. The problem could also be a cracked flex plate, which is much more common, but often difficult to see.
arveetek
01-08-2022, 19:33
Yes, long-term damage from bad harmonic vibrations has me concerned. I don't think it's the flexplate; it wasn't cracked before the install, and the vibration has been noticeable since startup after the engine/torque converter swap.
Casey
The instance of poor quality converter rebuilds is not a new one.
Proper jigs and fixtures are the key to producing quality parts...
When you get the converter out.....IF you can get access to a lathe that can swing it....grab the converter by the hub and gently clamp it..
Rotate the converter slowly by hand and observe the pilot on the front of the converter.
Also watch the entire outer rim of the converter for run out.
Before installing the replacement.....check it for run out as well
This sort of crap just sucks....
What brand of rebuilt .?????????
Rebuilt converters do not always get a fresh hub welded on.....If the hub surface is good they get used again.
So it's a crap shoot.
Well done Casey! Glad to read that it is up and running again!
So with the slower spooling of your Hx35w with new converter, do you feel any additional power or loss of power or is it about the same? Any difference with boost levels?
If you want a spare flex plate or starter, I have a few extra ones. Send pm if you do.
arveetek
01-29-2022, 16:39
6 months after blowing the head gasket, the ol' Tahoe is finally back on the road!
I replaced the defective torque converter, and now FINALLY everything is working like it should! The engine is running great, the torque converter is the correct stall speed, and there are no more vibrations! Hallelujah, praise the Lord!!
To recap:
July 2021 - the original 929 engine blew a head gasket after 378K miles.
I decided to rebuild a spare 506 engine I had pulled from a 1997 C2500 several years ago. That engine had lost compression due to a failed exhaust valve, but otherwise was in great shape.
November 2021 - engine is finally rebuilt and installed; I had decided to rebuild the transmission as well due to the high mileage; new engine ran great, but the transmission shop gave me a high-stall torque converter by mistake; very annoying to drive, so I order the correct torque converter.
December 2021 - after only 900 miles, the new engine lost compression on one cylinder; turns out another exhaust valve failed; apparently this engine had weak valves; engine was removed, and both heads sent back to the shop for all new valves. I used this opportunity to swap in the correct, low-stall torque converter.
January 2022 - the engine is reinstalled and runs great; however now there is a bad vibration that I determine is a faulty torque converter. The converter supplier sends me a replacement converter, and this time I drop the transmission and transfer case to swap the converter. The replacement converter is good, and now everything is running like it should!
So, the engine was removed and reinstalled twice, and the transmission was removed and reinstalled twice. I am so ready for this project to be done! But at least now I should have a long-lasting drivetrain.
Casey
SWEEEEEEEEEEEEEEEEEEEEEEEEET.....
So sorry you had to go through such a torturous path to get there.....
The Blazer should be good to go for many years now...
Good job.....And I know how you feel......
Yukon6.2
01-30-2022, 09:19
I hate it when you are working on something...
And you get so familiar working on it that you recognize individual fasteners,and when the power goes out you just keep on keeping on
Glad you have that behind you and you can enjoy your cool truck for years to come
arveetek
01-30-2022, 12:02
Thank you all! I'm so glad to finally be at the point where I can enjoy driving it again without worrying about that one thing that still needs remedied.
I hate it when you are working on something...
And you get so familiar working on it that you recognize individual fasteners,and when the power goes out you just keep on keeping on
So true! I know where every nut and bolt belongs on this rig! I can identify every single fastener now and tell you where it goes...
Casey
More Power
01-31-2022, 13:52
Good job Casey... for sticking with it. :cool:
trbankii
02-06-2022, 13:39
How's that saying go? "A job worth doing is worth doing two (three?) times..."
No... That can't be it... :rolleyes:
Glad to hear that you have it dialed in again. Here's to many miles of open road for you and the Tahoe!
arveetek
02-06-2022, 19:41
How's that saying go? "A job worth doing is worth doing two (three?) times..."
No... That can't be it... :rolleyes:
Glad to hear that you have it dialed in again. Here's to many miles of open road for you and the Tahoe!
Ha ha!
Thanks guys! I'm actually getting to enjoy driving it for a change!
Everything is going smoothly (knock on wood). I think I need to figure out a way to set the timing; I suspect it might be a tad retarded. Last time I set the timing, I had a buddy who was a GM tech who brought home a Tech II for me to use, but now he moved to Alabama. I don't know anyone else with the correct tools....
Casey
If the timing is out of spec the computer will start screaming (CHECK ENGINE LIGHT ON)
Whatever it was set to before you did the rebuild will be stored in the computer and come back up and go to work.....
If the actual position of the IP is off so far that the computer can't achieve the desired timing it will set a code...
If the light is not on....you are where you were before.....
What has lead you to believe the timing is off ?????
A lot changed in the engine since you rebuilt it.....Fresh injectors for one.....
arveetek
02-07-2022, 07:14
What has lead you to believe the timing is off ?????
The engine doesn't have has much diesel clatter as I would expect, and the idle is just a little rough; not as smooth as I would like. When it's cold and the timing is advanced, it runs more like I think it should.
It's a different engine, with the front timing cover and pump from the original engine. I scribed the pump to the front cover before removal, so it should be pretty close, but I just assumed it's not spot on.
Casey
Hmmmmm
The timing "spot on" is controlled by the computer....Moving the pump physically will not change things unless you go outside what the computer can adjust things....then the SES light will come on due to the timing being "out of range"
Injector POP PRESSURE can have a big effect on "Diesel Rattle" and depending on variations in the POP it can cause slight roughness in the idle as can other injector issues such as the spray pattern....A poor or odd spray can cause roughness too.
Were the injectors new or rebuilt ???
arveetek
02-07-2022, 09:07
Hmmmmm
Were the injectors new or rebuilt ???
Brand new Bosch
DmaxMaverick
02-07-2022, 12:56
Stock timing is fairly tame (retarded). Was the TDCO ever optimized (-1.50 to -1.94)? If it was, it may not be, now. You can turn the pump toward advance a little at a time. Stop and back up the tiniest bit when the computer complains.
arveetek
02-07-2022, 20:45
Stock timing is fairly tame (retarded). Was the TDCO ever optimized (-1.50 to -1.94)? If it was, it may not be, now. You can turn the pump toward advance a little at a time. Stop and back up the tiniest bit when the computer complains.
Yes it was, years ago. I wasn't sure if advancing the pump would actually accomplish anything or not without having the computer relearn the new position.
Casey
More Power
02-08-2022, 12:41
1mm movement at the pump flange's scribe line equals about a 2 degree change in timing. Sarah's Blazer is a little bit advanced from where it could be. I tried to line up the scribe lines during the install. I may leave it there... I dunno. Or I may have a TDC-Offset performed using the -1.5-1.94 setting Greg mentioned... assuming I can find someone with both a Tech II the skill to do it.
I've also thought about just retarding the pump a smidge at a time (<1/16") till it sounds familiar. I think it'll work that way... without redoing the TDCO. It's easy enough to try. Robyn may be right, but it's been a while since I've studied the process.
I am pretty sure that the actual timing is done by the stepper motor in the DS4 and the computer places the internals of the pump where it needs to be to accomplish the setting.
If you rotate the pump itself and the computer can't get the desired setting then it will complain.......At the factory ....I am told that the IP is placed in a "Given physical location" that will allow enough internal movement for the electronics to achieve the desired settings.
Scribing the pump and the cover will get things close enough so the computer can do it's job and not complain......This will allow the pump to be removed long term during a rebuild and then go back to work without a hitch.
I have never seen the actual fixture used to align the IP on the DS4 with the cover.....but there is one.......
DmaxMaverick
02-09-2022, 08:52
Yes, just rotating the pump won't change the timing. If it seems too advanced, that's where the PCM wants it, and it's probably correct if near OEM position. The PCM compares the crank and cam (pump) sensors, and times accordingly. That is, unless the pump is moved to an extreme the stepper can't compensate past, and the reason TDCO optimization works, by rotating the pump to the advanced extreme either before, or to the limit of compensation (-1.94) window. It can be done by hit/miss moving the pump, or using the learn procedure (scanner not required for OBD-I, but I don't recall the KO/Ko hoops to jump). The PCM will relearn TDCO, itself, over time. Same result, although one is initially virtual, vs. actual. The TDCO is built in to compensate for normal valve train wear. Exceeding -1.94 and associated DTC's are the PCM telling you the pump is broken, or the valve train is worn beyond the computer's ability to compensate.
If you feel the timing is too advanced, TDCO optimization will only increase the advance. Retarding the timing requires programming, or a chip for OBD-I. Who would really want to do that?
Just a whatever it is worth....
I have been through several 6.5 with OBD1 electronics...(94-95 models) and every engine ran and sounded different after the rebuild.
One 94 we had would make an old 7.3 Power Stroke blush on a really cold start.
OMG IT RATTLED.....Ran great though.
That engine ended up with a set of Clearwater heads.
The after market precups in the heads may have been a contributing factor.....?????????????????? Don't know...
The Dahooooley rebuild the first time when we ended up with the block that had been decked too much has a specific sound and feel.
It had a set of 1992 heads on it......Matching cups.
The second time around the block was an AMG block, Scat crank, GM rods, After market pistons and New AMG heads.....
The injectors were fresh rebuilds from Diesel fuel injection service up in PDX (Same parts just swapped them)
DS4 was swapped along with all the rest of the gear.
These two engines were as different as daylight and dark.
Same Heath diesel chip in the ECM
All together different feel and sound.......VERY VERY SMOOTH the last time....
It is hard to compare a used engine with lotsa miles on the clock to a fresh build.....Too many subtle changes that can effect the BUTT DYNO....and what you hear.
Enjoy the fresh power plant ....it's a different little person....
More Power
02-10-2022, 13:31
The 6.5TD Power Project I put together in 1999 had a pretty raucous rattle when cold and when the hood was up. Part of that was the DSG gear drive, which had some timing advance built-in. The 18:1 pistons may have had an effect too. On the highway though at 65-mph, the rattle was only barely detectable from inside the cab. Sarah's Blazer is like that too... the rattle is only barely detectable at 65-mph.
arveetek
02-10-2022, 15:45
My new engine is a little unusual to me.... it sounds great from inside the cab; sounds nice and healthy at idle with the amount of rattle I would expect; very smooth at all rpm above idle; idles perfect (to me) when cold.
However, if I step OUTSIDE the cab and the engine is warmed up, the idle seems a little rough with not as much rattle as I would expect. However, I'm wondering if it might be my old exhaust system (3.5" exhaust I pieced together years ago). If I pop the hood and stand next to the engine, I think it sounds great; but close the hood and listen to the exhaust, it just sounds... weird... to me anyway. That's why I was thinking maybe the engine timing could be advanced a bit....
Kinda hard to explain in words. But having driven 5.7L/6.2L/6.5L diesels for 27 years, I kinda expect them to sound a certain way. But this is my first 6.5L that I've completely rebuilt.
Come to think of it, the 6.2L I previously built sounded about the same after I rebuilt it. I always thought it had a weird idle when I was finished. Hmmmm.....
Casey
Yukon6.2
02-11-2022, 09:16
Maybe it's the Casey touch putting in a signature rattle...
Or are you missing any tools?
a5150nut
02-11-2022, 12:38
Kinda like the last 100 miles of a long trip. Everything starts to sound weird.
arveetek
02-11-2022, 12:53
Maybe it's the Casey touch putting in a signature rattle...
Or are you missing any tools?
LOL! Nope, no missing tools. I didn't even have any leftover nuts or bolts! I was pretty proud of that. :D
Casey
Yukon6.2
02-12-2022, 09:45
I grew up living on a Highway Lodge in remote Yukon
I spent my free time watching my Dad fix stuff.
In the gas shortage of the 70's VW's became popular.The highway we were on was gravel at the time.The VW's had a area where they dies on the way up from Haines Alaska.They ran fine on pavement without oil in the oil bath air cleaners,but the dust killed them off.
One engine rebuild my Dad did there was a putty knife inside when he split the crankcase
One truck tire fix came with a nice hammer in it,split rim tube type tires.
Tools and where they end up...
convert2diesel
02-12-2022, 13:00
Back in the 70s, during my aircraft years, the local SnapOn guy had the ring spanner end of a 9/16 wrench mounted to a board in his truck. Said it was the most expensive wrench ever made. Turns out the whole wrench was left in the intake of a turbine engine. Took out the entire compressor section and a few parts of the hot section. Only the ring spanner end survived.
A 200,000 dollar mistake :mad:
Bill
Hope it didn't have the owner's name engraved on it... ;)
First thing the men I worked with told me right after I got out of A&P school in '74. Do_not_engrave your name on your tools.
arveetek
02-22-2022, 20:50
With nearly 1200 miles on the the new engine, my son and I decided it was time to test it out under a load. On Saturday, we loaded up our antique John Deere B onto the flatbed and went for a drive. I was quite pleased with the results!
First off, the HX35 turbo with the TurboMaster wastegate set to its lightest setting seems to produce a maximum of 15 psi under full throttle between 2500-3500 rpm. I am comfortable with that pressure. EGT's hovered around 1050 at the same time. This was under relatively short duration pulls on a large hills (about a mile long each), but I was giving her all she had. Longer pulls in hot weather may produce different results.
With the original engine, I was only able to maintain speed (65 mph) on both of these hills; now, I was actually able to accelerate and had to back off the throttle to keep speed in check. That was a nice surprise!
Also, engine coolant temp seems to be much more stable; again, this was cool weather (ambient temp was actually a nice 55* on Saturday), but every time I have ever towed before (no matter the ambient temp), the coolant temp would always climb steadily on hard pulls. I had performed every cooling upgrade possible, but my original engine would ALWAYS run hot when towing. However, I couldn't get the needle to move on this test. I can't wait to test under summer towing conditions.
It was only about a 40 mile round trip test, but initial results were quite promising. I can't wait to hitch up the camper and go for a trip to see how she does in a better, real-world test.
I haven't checked MPG empty yet; I did top off today (about 10 gallons), and with the towing mixed in (with a lot of full-throttle pulls), I achieved 14.5 mpg. I'll try to get an accurate reading on this tank I have now.
Casey
Sounds great.
Having the coolant temps stay steady is a very good thing.....
Looks like a winner.....;)
More Power
03-24-2022, 13:13
With nearly 1200 miles on the the new engine, my son and I decided it was time to test it out under a load. On Saturday, we loaded up our antique John Deere B onto the flatbed and went for a drive. I was quite pleased with the results!
First off, the HX35 turbo with the TurboMaster wastegate set to its lightest setting seems to produce a maximum of 15 psi under full throttle between 2500-3500 rpm. I am comfortable with that pressure. EGT's hovered around 1050 at the same time. This was under relatively short duration pulls on a large hills (about a mile long each), but I was giving her all she had. Longer pulls in hot weather may produce different results.
With the original engine, I was only able to maintain speed (65 mph) on both of these hills; now, I was actually able to accelerate and had to back off the throttle to keep speed in check. That was a nice surprise!
Also, engine coolant temp seems to be much more stable; again, this was cool weather (ambient temp was actually a nice 55* on Saturday), but every time I have ever towed before (no matter the ambient temp), the coolant temp would always climb steadily on hard pulls. I had performed every cooling upgrade possible, but my original engine would ALWAYS run hot when towing. However, I couldn't get the needle to move on this test. I can't wait to test under summer towing conditions.
It was only about a 40 mile round trip test, but initial results were quite promising. I can't wait to hitch up the camper and go for a trip to see how she does in a better, real-world test.
I haven't checked MPG empty yet; I did top off today (about 10 gallons), and with the towing mixed in (with a lot of full-throttle pulls), I achieved 14.5 mpg. I'll try to get an accurate reading on this tank I have now.
Casey
Sound great! Long pulls at 15-psi could use an intercooler. Otherwise, as you've discovered, a more efficient turbocharger helps with EGT. The HX-35 is a really good choice for a more or less stock engine and fuel injection system - especially when towing.
arveetek
03-24-2022, 14:28
Sound great! Long pulls at 15-psi could use an intercooler. Otherwise, as you've discovered, a more efficient turbocharger helps with EGT. The HX-35 is a really good choice for a more or less stock engine and fuel injection system - especially when towing.
An intercooler is definitely on my short list for needed upgrades. I want this engine to last a long time, and I think an intercooler is the most important upgrade I could make next.
Casey
arveetek
04-18-2022, 19:27
The ol' Tahoe is running great! No issues now after approx. 2,500 miles. Any weird sounds have either disappeared or I've gotten used to them. Seems like she idles smoother now.
I was a bit worried about the fuel mileage at first. After a 1,000 mile break-in period, I started logging the mileage. My first tank came back at 14.5 mpg! That shocked me; I had never seen that low of daily driving mileage before. I usually saw a consistent 17.5 mpg. Best tank I ever had was 18.5 mpg on a road trip one time.
But every tank since then has improved. The next tank was 15.5; then 16.1. Today I recorded 16.85 mpg.
I don't think my driving habits have changed that much; it's quite possible that early on I was really mashing the go pedal and enjoying the turbo spooling up; I may be driving more conservatively now, but it's also possible the engine is still breaking in.
Hoping that soon I'll see the 18 mpg I was getting before.
Casey
Likely all of the above.....
trbankii
04-28-2022, 18:48
Great to hear!
a5150nut
04-29-2022, 10:40
Good to follow one of these threads that comes to a good end.
More Power
05-01-2022, 15:20
The ol' Tahoe is running great! No issues now after approx. 2,500 miles. Any weird sounds have either disappeared or I've gotten used to them. Seems like she idles smoother now.
I was a bit worried about the fuel mileage at first. After a 1,000 mile break-in period, I started logging the mileage. My first tank came back at 14.5 mpg! That shocked me; I had never seen that low of daily driving mileage before. I usually saw a consistent 17.5 mpg. Best tank I ever had was 18.5 mpg on a road trip one time.
But every tank since then has improved. The next tank was 15.5; then 16.1. Today I recorded 16.85 mpg.
I don't think my driving habits have changed that much; it's quite possible that early on I was really mashing the go pedal and enjoying the turbo spooling up; I may be driving more conservatively now, but it's also possible the engine is still breaking in.
Hoping that soon I'll see the 18 mpg I was getting before.
Casey
As I recall, your Tahoe has 3.42 gearing... My 3.42 geared 1982 GMC K1500, with a fresh 6.2L and Banks turbo and TH700R4, would deliver 24 mpg commuting 50miles/day. I checked dozens of tanks of fuel to get that number. It was super efficient. I suspect some of the fuel mileage we're both seeing (Sarah's Blazer is doing about the same as your Tahoe) is due to the DS4. I'd wager a few bucks that if we were to install a DB2 fuel injection pump, the mileage would be better.
I've read about the TH700 being a more efficient transmission than the 4L80-E. That may be some of it.
Sarah's Blazer engine is equipped with the small port precups, as it was from the factory. Our 6.5TD Power project truck, with 4L80-E, 4.10 gearing, and a DB2 marine pump would consistently deliver 17-18 mpg. That engine had the large port precups. It delivered 21-mpg once when driving between Lolo MT and Lewiston, ID on US-12. (slow winding road, averaging about 60-mph, slightly downhill - a river valley - most of the way).
Jim
arveetek
05-02-2022, 05:59
As I recall, your Tahoe has 3.42 gearing... My 3.42 geared 1982 GMC K1500, with a fresh 6.2L and Banks turbo and TH700R4, would deliver 24 mpg commuting 50miles/day. I checked dozens of tanks of fuel to get that number. It was super efficient. I suspect some of the fuel mileage we're both seeing (Sarah's Blazer is doing about the same as your Tahoe) is due to the DS4. I'd wager a few bucks that if we were to install a DB2 fuel injection pump, the mileage would be better.
I've read about the TH700 being a more efficient transmission than the 4L80-E. That may be some of it.
Jim
You are correct; I have 3.42 gears and 33" tires (and the speedometer has been corrected). My old '81 C20 2WD project that I had equipped with a 6.2L turbo, 700R4, and 4.10 gears with 31" tires used to consistently average 19 mpg, even though it had a much higher cruising RPM.
The only GM diesel I've had that broke the 20 mpg mark was my old '77 Blazer 2WD project that I had swapped in a 5.7L diesel with 3 speed auto. It would get close to 25 mpg, but couldn't use the passing lane since it was so gutless! :D
Casey
Mileage on these rigs can be all over the map.
We had a 1986 Suburban K2500 4.10 gears Turbo 400 trans
Stock tires and wheels.
On the road it would consistently deliver 26 mpg and on a trip from home to Long Beach California it did 28 mpg on the leg from Sacramento to just before the grapevine (Flat easy running on cruise control)
Around town it ran on average about 22 mpg
More Power
05-09-2022, 08:52
...clip...
First, I made a bypass hose to make a circuit on the oil cooler ports:
https://live.staticflickr.com/65535/51647353026_864cd9cefd_b.jpg
...clip...
Casey
I've spoken to a guy here recently who called to talk about why his 6.5 was losing oil pressure after warming up. It would be fine, then he'd lose almost all oil pressure... We talked about the possibilities I knew about on that first call.
On the second call I learned sorta accidentally that he had put plugs into the oil cooler line ports on the block. His original lines were leaking and he "didn't think they were necessary". I told him that if the oil cooler line circuit was to become blocked, it'll force a bypass valve to open. I continued by saying that I didn't know what the ultimate consequences would be, but an odd response in oil pressure would be expected...
Like you, I made a looped bypass when I primed the oiling system on Sarah's 6.5 while it was on the engine stand.
Jim
arveetek
05-10-2022, 12:06
We had our first camping trip of the season this past weekend, and it was the first time I really had an opportunity to work the new engine pretty hard. Overall, I'm really pleased with the performance of the engine and upgraded turbo. I was a bit concerned the HX35 turbo might produce too much boost, but on long, somewhat steep grades with the transmission locked in 3rd and the engine at around 2500 rpm, the boost stayed steady between 10-12 psi with EGT's hitting a max of 1150*. The coolant temps were more stable than before as well; the old engine always ran hot, even with every 6.5L cooling upgrade available. I'm beginning to suspect the coolant passages may have been blocked with sediment. The new engine never even reached the halfway/210* mark. It would start to climb a bit, the engine fan would kick in, and then the temp would come back down to around 185*. This was with the A/C on and the ambient temp about 83*. Much better results than before.
All in all, even with just a stock build, the engine seems to have more power and pulls strong. There is a bit more turbo lag, though, as it blows a ton of black smoke until the engine can build up a bit more RPM and then the exhaust clears up and just keeps pulling. I can hit 15 psi in the upper RPM range at full throttle, so I do keep my eye on the boost gauge, but it doesn't get that high as easily as I thought it might.
An intercooler is next on my radar. I want to make sure this engine lives a long life.
Couple of pics of my rig below. 1995 Tahoe towing a 2017 Springdale 1800BH; trailer weighs approx. 4500 lbs and is 21' long; it's not a huge trailer, but is a pretty good load for a short-wheelbase 1/2 ton vehicle.
First pic is at Devil's Tower in Wyoming about 3 years ago; second pic is north of Mulberry Mountain in Arkansas:
https://live.staticflickr.com/65535/52064998510_b71a1a843a_h.jpg
https://live.staticflickr.com/65535/52063467072_833fe1494e_h.jpg
Casey
More Power
05-10-2022, 12:59
Great pics Casey! Looks and reads like fun!
So glad to hear that the little beast is gittenerdone......Makes all the work and rework all worth the effort.....
Enjoy.....
DieselDavy
05-22-2022, 17:31
Way to go Casey!
Sounds like you did a great job!
d
arveetek
05-26-2022, 13:40
After 4,000 miles, fuel mileage is still low. My best tank so far has returned 16.5 mpg, but the last two tanks returned 16.1 mpg. I'm a little disappointed, as I averaged a consistent 17 to 18 mpg with the old engine. But from the other posts I've read, 16 seems to be average. I'm not sure why the mileage would be lower, with a fresh overhaul and new injectors. Perhaps the engine could still use some more break-in time?
Casey
We had our first camping trip of the season this past weekend, and it was the first time I really had an opportunity to work the new engine pretty hard. Overall, I'm really pleased with the performance of the engine and upgraded turbo. I was a bit concerned the HX35 turbo might produce too much boost, but on long, somewhat steep grades with the transmission locked in 3rd and the engine at around 2500 rpm, the boost stayed steady between 10-12 psi with EGT's hitting a max of 1150*. The coolant temps were more stable than before as well; the old engine always ran hot, even with every 6.5L cooling upgrade available. I'm beginning to suspect the coolant passages may have been blocked with sediment. The new engine never even reached the halfway/210* mark. It would start to climb a bit, the engine fan would kick in, and then the temp would come back down to around 185*. This was with the A/C on and the ambient temp about 83*. Much better results than before.
All in all, even with just a stock build, the engine seems to have more power and pulls strong. There is a bit more turbo lag, though, as it blows a ton of black smoke until the engine can build up a bit more RPM and then the exhaust clears up and just keeps pulling. I can hit 15 psi in the upper RPM range at full throttle, so I do keep my eye on the boost gauge, but it doesn't get that high as easily as I thought it might.
An intercooler is next on my radar. I want to make sure this engine lives a long life.
Couple of pics of my rig below. 1995 Tahoe towing a 2017 Springdale 1800BH; trailer weighs approx. 4500 lbs and is 21' long; it's not a huge trailer, but is a pretty good load for a short-wheelbase 1/2 ton vehicle.
First pic is at Devil's Tower in Wyoming about 3 years ago; second pic is north of Mulberry Mountain in Arkansas:
https://live.staticflickr.com/65535/52064998510_b71a1a843a_h.jpg
https://live.staticflickr.com/65535/52063467072_833fe1494e_h.jpg
Casey
Have you researched the made in China Hx35w? I’ve read that they spool faster and have less lag.
On my work bench is a good used Holset Hx35w and next to it is a made in China one. With my finger, I can spin the compressor wheel easier then the Holset. The Holset is lubed but the China one is not. Could be worth giving it a try on your build.
On an older build with both Holset and made in China Hx35w lubed the China one for sure had less resistance.
With my build, I set a strict rule for myself with regards to the Egts. Having the Egt probe on the square dimple of my exhaust manifold, I feel safe to assume that whatever reading I am getting on the pyro gauge, I increase 200 more degrees in my head. Internally, it will always be hotter then what the probe reads. So to be safe, 900 degrees is the max I will ever push it.
After 4,000 miles, fuel mileage is still low. My best tank so far has returned 16.5 mpg, but the last two tanks returned 16.1 mpg. I'm a little disappointed, as I averaged a consistent 17 to 18 mpg with the old engine. But from the other posts I've read, 16 seems to be average. I'm not sure why the mileage would be lower, with a fresh overhaul and new injectors. Perhaps the engine could still use some more break-in time?
Casey
That’s about what I am getting. I always push it hard.
arveetek
07-09-2022, 10:04
My family and I just returned from a 13 day camping trip using the Ol' Tahoe to tow our 21' camper over 1100 miles.
Before we set off on our trip, I wanted to address the air filter situation. With the new HX35, the original air cleaner would not hook up, since the old turbo had a 3" inlet and the new turbo has a 4" inlet. I had temporarily installed a universal 4" filter right onto the turbo, but this was not a good situation since it was pulling in hot, under-hood air:
https://live.staticflickr.com/65535/51708600507_52a3e84664_b.jpg
I wanted to alleviate this problem before towing the camper up hills in near 100* temperatures. It finally dawned on me that I could simply cut out the opening of the original air filter housing to allow the larger 4" silicone hoses to fit inside. (Years ago I had swapped the 1995 flat-style filter for the 1997+ round filter housing.) So I had to order two new 90* 4" silicone hoses (since I had modified the first set to where I couldn't use them again), cut them down slightly, and bingo! The 4" K&N filter now tucks neatly inside the 1997 housing drawing air from the driver's side fender:
https://live.staticflickr.com/65535/52204522646_f6376ed696_c.jpg
https://live.staticflickr.com/65535/52203518482_94c09fc1ca_c.jpg
The only draw back to this setup is now I can't hear the turbo as much! :( With the open element on the inlet of the turbo, the whistle was fantastic at nearly all speeds. Now, I can only hear the turbo when under load at pressures above 10 psi (which still sounds pretty sweet, though!).
With that, we set off on a 2 week trip to tour 5 different Missouri State parks. The trip would take us on a loop from our house in SW Missouri, heading east and stopping at 3 different parks that finally put us close to St. Louis before circling back west and ending up at Lake of the Ozarks. We encountered several hilly roads and some fairly steep grades. Here are the results of towing with the new engine:
Cooling - by far, the biggest improvement over the old engine is the cooling! Before, the old engine would always run hot, struggling to keep cool no matter what. I had every possible cooling upgrade on the old engine, but the temp would always climb on any incline or hard throttle input. I constantly had to keep one eye on the temp gauge. The fan clutch would usually stay engaged at all times, and the temp gauge would get dangerously close to the red line. It would never run cooler than 210* with the trailer on, usually hanging out closer to 220*.
Now, however, the temp never went above 210* (halfway on the gauge). In fact, it often ran around 190*, and the fan would kick on and off as needed, even with ambient temps in the upper 90's. (I have 180* thermostats.) It has never run this cool before. I wish I could identify why this is, but with a different engine block, different heads, different turbo, etc. there's no way to know which of these changes made the difference. I am starting to suspect the old engine may have had sediment filling up the cooling passages?
Boost - I was a bit concerned with having too much boost with the HX35, but unless I was pushing full throttle at high RPM (such as 2nd gear, 3000 RPM), it was not an issue. Most of the time, hard throttle in 3rd gear saw around 10 -13 psi. I saw a peak of 15 psi at high RPM situations, but rarely. I feel comfortable with those numbers, but would still like to have an intercooler to cool the charged air. The TurboMaster is backed nearly all the way off. EGT's on hard pulls were 1000 - 1150, with some short peaks of 1200 from time to time.
Power - Power is a bit better than the original engine. This is a stock rebuild 506, so the only power upgrades over the old 929 engine would be the diamond pre-cup HD heads, brand new injectors, and the HX35 turbo. My biggest issue is the 3.42 gears with 33" tires, so it's not built to be a towing machine. I had all the power I really needed for this size of trailer, but towing at highway speeds is an issue, since 4th gear lugs the engine too much, and 3rd limits my speed to about 65 mph to keep the RPM at 2500 or less.
Fuel economy - This is still a concern area. We had one long stretch of 4 lane highway that I pushed her hard to keep up with traffic (67 mph, 2600 rpm in 3rd), and that tank came back up at only 8.47 mpg!! I was shocked. After that, I backed the speed down closer to 62 mph, and used less of the cruise control. I noticed that with the cruise on, the ECM was often commanding a lot more fuel to keep up the speed, whereas if I just let it slow down a little on the hills, I would use much less fuel. After that, I averaged 10-11 mpg on the following tanks. Overall, after 1100 miles round trip, I averaged 11.7 mpg for the whole trip. I still think it should be better than that, but again, the 3.42 gears and 33" tires hurts the towing mileage for sure.
I had zero issues on the trip (other than my hood latch release handle broke for some reason... I must have hit it with my foot. Still works, though). I didn't have to make any repairs on the whole trip! Very strange for an RV trip! :D I am pleased with the overall performance of this 27 year old vehicle with 382K miles on the body, and am super happy with the lower engine temps. However, If I ever head back west towards the mountains again, I really need to consider a newer, more powerful tow vehicle. Today's modern roads with speed limits of 70mph + is just hard to manage with this kind of vehicle with a trailer on the back.
Some pics of trip:
https://live.staticflickr.com/65535/52204542628_4905b607cc_c.jpg
https://live.staticflickr.com/65535/52205026390_1fd7d8b390_c.jpg
https://live.staticflickr.com/65535/52204522566_33d62973a4_c.jpg
https://live.staticflickr.com/65535/52204522541_48ec8ea977_c.jpg
https://live.staticflickr.com/65535/52203518417_284a8b00e2_c.jpg
Casey
DmaxMaverick
07-09-2022, 11:04
Sounds like a fantastic trip, Casey. Nice pics. No repairs is a huge bonus (better knock wood, quick).
Your gear ratio is too high (no surprise). Wrong gears, as you've seen, absolutely kills economy. I've run into this several times over the years when upsizing tires, and the only solutions have been either downsizing, or a re-gear. I just happen to have a complete 3.73 front diff from a 1995 GMC 1500. If it fits, and you take it up, you'll have to either swap your rear end or swap in the gears. It's just taking up space here, so it's yours for cheap + shipping. I'd even send just the R/P gears and, if you want. Check costs locally to see if you can beat it.
arveetek
07-09-2022, 15:04
Sounds like a fantastic trip, Casey. Nice pics. No repairs is a huge bonus (better knock wood, quick).
Your gear ratio is too high (no surprise). Wrong gears, as you've seen, absolutely kills economy. I've run into this several times over the years when upsizing tires, and the only solutions have been either downsizing, or a re-gear. I just happen to have a complete 3.73 front diff from a 1995 GMC 1500. If it fits, and you take it up, you'll have to either swap your rear end or swap in the gears. It's just taking up space here, so it's yours for cheap + shipping. I'd even send just the R/P gears and, if you want. Check costs locally to see if you can beat it.
That's awesome, Greg, thanks! I've been wanting to swap gears for some time, but having to do both front and rear at the same time has held me back. I will check into that and let you know. Thanks!
Casey
DmaxMaverick
07-09-2022, 15:25
I did something similar some decades ago with my 85. I upsized from the OEM 31" tires to 33" mudders (no lift needed). Economy and power was sapped. Re-gearing from 3.73 to 4.10 put it right back were it was before (including the speedo), with only a little loss of economy. I could have (and perhaps should have) added a turbo instead, but didn't. I never felt like I needed more power. I did the rear end first, mostly because it wouldn't cost me any more at the time, as I was already building a 12-bolt rear end to replace the twice-blown 10-bolt. I did the front end more than a year later.
a5150nut
07-09-2022, 17:33
Your giving me a bad case if hitch fever talking about your trip.
Tire size and gearing is critical. My 06 K3500 would look so much better with 285s but I would need to re gear to keep Duramax and Alison in the sweet spot. When I left California December of 14 I pulled a 36ft fith wheel to Carson City Nevada then on to Hurricane Utah, thru North end of Grand Canyon to Santa Fe NM. From there were came across to Knoxville TN. We had been living in the fifth wheel for 15 years and accumulated to much junk. I scaled it before leaving CA and was only 500 lbs below max for the truck.
Kept an eye on EGTs and let the truck do its thing. Sure was glad I had this truck and not my 94 K2500 it would have been to much for it even with the five speed. Managed to enhance millage on my trip by finding a semi to pace with and just slide in behind them. I could tell when I hit the sweet spot, boost would drop along with EGTs.
Yo have a sweet ride there I hope you enjoy it for a long time.
arveetek
07-10-2022, 19:40
Your giving me a bad case of hitch fever talking about your trip.....
You have a sweet ride there I hope you enjoy it for a long time.
Thanks!
Our family loves to travel, especially with the camper. I'm never ready to go home at the end of a trip. I am 46 years old, and the longest trip I have been on at one time is 3 weeks. Even at that, I still wasn't ready to go home. If it wasn't for that pesky job and needing to make an income, I would love to full time RV right now.
I've had this rig for for 17 years now, and I don't plan to let it go. My wife has mentioned more than once that we could sell it to get something newer, but I won't let it happen. It's just too unique. I often get comments at the fuel station and other spots... a lot of folks can't believe it's a factory diesel. My son would never forgive me if I were to ever sell it (he's 12 and loves it).
Casey
More Power
07-12-2022, 08:32
Casey,
Great story! Thank you for posting the pics and story.
Here's a quote from what was written about our 4.10 geared 6.5TD Project truck and towing a 27' travel trailer...
Two thousand miles from our home in western Montana, we stop at a rest area in Indiana, on our way to Dayton, Ohio and The Diesel Page 2001 Rendezvous. This towing excursion added 4,500 miles to the odometer, and produced a 10.8 mpg average for the entire trip. While on the interstate highways, we tend to run at about 70-mph with a combined truck and trailer weight of more than 13,500-lbs.
https://www.thedieselpage.com/finale.htm
I'm mentioning this here to help with expectations. Yes... a newer or more powerful truck could tow faster, but it really hurts the fuel economy, even with a new truck. I know from towing a 14' camper trailer with an NA 6.2L diesel how wind resistance affects towing. The power required to tow is logarithmic with speed. With my 6.2L NA, wind resistance created a barrier at 65-mph that could not be crossed.
These engines like to tow at about 2000-2400-rpm. Of course, your Holset changes things some, but the DS4 power delivery still likes that engine speed. I agree with others here about gearing, the 4.10's would help, but it's a little spendy to swap gearing. When I eventually turbo'ed my 6.2L 1982 GMC with a Banks Sidewinder (which had 3.42 gears and a TH700R4), I eventually settled into a routine while towing... If the tow situation was easy, I'd run in OD. If there was a headwind or slight incline, I'd run in 3rd, and speed was determined by where the engine seemed happy. I also tended to stay on secondary roads when possible just because it made for a more enjoyable trip.
Improved cooling.... the 1997+ cooling mods, a fan-clutch that engages when it should, and the Holset.
Thanks again for the pics!
arveetek
07-23-2022, 07:34
I am contemplating a gear ratio change. The Tahoe came equipped from the factory with 3.42 gears and 30.5" tires. I upgraded to 32.8" tires years ago, and as a result, the engine has never been in the proper power band when towing.
I did some calculations for various gear ratios, and came up with the following info:
https://live.staticflickr.com/65535/52235690001_3fcf81fdde_z.jpg
Swapping to 3.73 gears would put me back to near factory settings. However, 4.10's would obviously gain more power. I'm just concerned 4.10's would not be the best for everyday driving.
On my old '81 C20 project truck with a 6.2L turbo diesel and 700R4, I ran 4.10 gears with 30.5 tires. The 700R4 had a steeper Overdrive ratio, though, so my cruising RPMs were still pretty decent. The truck delivered a consistent 18 mpg when empty, and had decent power when towing.
What would you do if you were in my shoes? Go with 3.73 to keep it close to factory gearing, or go for 4.10's to get the most power when towing. This is my daily driver, but we do tow our camper several times a year, and sometimes on some pretty long trips. I am obviously asking for the impossible, but would like to have both: the best MPG when empty and the most power when towing.
Casey
How is it currently for unloaded? How about the Gear Vendors as an underdrive for towing? Plus, you can call it an 8 speed...
arveetek
07-25-2022, 06:26
How is it currently for unloaded? How about the Gear Vendors as an underdrive for towing? Plus, you can call it an 8 speed...
Just fine when unloaded, though the mileage seems a bit low. I don't want to spend the $ on a Gear Vendors, plus I don't think there's room for one any way. The driveshaft is really short as it is on this short wheelbase 4x4.
Casey
I don't want to spend the $ on a Gear Vendors
How does it compare to changing both ring and pinion sets? (Moot if it won't fit!)
arveetek
07-25-2022, 07:29
How does it compare to changing both ring and pinion sets? (Moot if it won't fit!)
If I change gears, my plan would be to replace the entire rear axle; I would remove the current 10 bolt and go with a semi-float 14 bolt 6 lug. My local U-Pull yard sells complete axles for under $300. The trick will be finding the correct axle and gear ratio. Then I would just need to regear the front diff. Should be considerably less than a Gear Vendors.
Casey
Yukon6.2
07-25-2022, 09:47
Or...
buy a donar with the gear ratio you want in front and rear diff's and change them both.If you watch and not in a rush you may get lucky and end up with cheap diffs and some stuff to sell to cover the costs.
trbankii
08-01-2022, 03:43
That's what I did. I picked up a pickup for $800 for the axles and manual transmission plus got a spare t-case and other parts.
arveetek
10-29-2022, 17:14
The Ol' Tahoe has 11K miles now since the rebuild was completed back on New Year's Eve. I've had zero problems with the engine or transmission, except for one small minor issue: I've noticed the past few weeks that on cold mornings the engine would miss just a little and blow a little more smoke for a few seconds at cold start. I could tell one cylinder wasn't firing right away.
While changing the oil today and checking things over, I discovered the problem: one of the glow plugs had a broken wire. The terminal had broken off the end of the wire. Naturally, it was one of the most difficult to access: number 6 right behind the down pipe. Thankfully I was able to wiggle the heat shield out of the way without too much problem and get to the glow plug.
Here is the wire as I found it just laying on the frame:
https://live.staticflickr.com/65535/52463433976_7a1a0a7265_c.jpg
https://live.staticflickr.com/65535/52463892560_24c24ba553_c.jpg
I was able to put a new terminal on the end of the wire, and all is good!
Casey
Glad it was a simple issue....
One of the Burbs we had in years past was getting really hard to start......I removed the plugs that were the easy ones....Two on the Right side were not wanting to come out of the head, so I decided to leave them and not risk breaking them off.
All the others got replaced.....Yeah it smoked a bit during a cold start.....But no worries....
Not worth breaking the plugs off and having a big mess to fight..
RH side anything on these engines is usually not fun......
More Power
11-01-2022, 09:53
I was able to put a new terminal on the end of the wire, and all is good!
Casey
Good job!
arveetek
11-11-2022, 12:19
I recorded my best fuel mileage to date with the new engine yesterday: 17.35 mpg. It had been hovering around 15.5 to 16.5 previously. I'm hoping that wasn't a fluke and that she's finally getting broken in and will keep providing better fuel economy.
Casey
More Power
11-18-2022, 10:40
I recorded my best fuel mileage to date with the new engine yesterday: 17.35 mpg. It had been hovering around 15.5 to 16.5 previously. I'm hoping that wasn't a fluke and that she's finally getting broken in and will keep providing better fuel economy.
Casey
That's encouraging!
I'd like to experiment with Sarah's Blazer in an effort to improve fuel economy... First up, install a DB2, though it's not quite that easy. My Banks 6.2L TD 1982 GMC would get 24+mpg at 65-mph. I was always a little disappointed that this Blazer, with 3.73 gearing, produced 5-7 mpg less. That 1982 GMC had a TH700R4 and 3.42 gearing, but I'm guessing the 6.5 would do better with a DB2 than it does with the DS4. But, it would be a costly experiment - a good DB2, fuel injector line set and electronics package (TCM/harness) for the 4L80-E... ~ A couple grand... to experiment.
From your summer post...
Fuel economy - This is still a concern area. We had one long stretch of 4 lane highway that I pushed her hard to keep up with traffic (67 mph, 2600 rpm in 3rd), and that tank came back up at only 8.47 mpg!! I was shocked. After that, I backed the speed down closer to 62 mph, and used less of the cruise control. I noticed that with the cruise on, the ECM was often commanding a lot more fuel to keep up the speed, whereas if I just let it slow down a little on the hills, I would use much less fuel. After that, I averaged 10-11 mpg on the following tanks. Overall, after 1100 miles round trip, I averaged 11.7 mpg for the whole trip. I still think it should be better than that, but again, the 3.42 gears and 33" tires hurts the towing mileage for sure.
Just as a frame of reference.... Our 6.5TD Project truck did the run from Montana to Dayton Ohio and back in 2001, while towing a medium sized 5th-wheel travel trailer - that trailer probably weighed about 7,000-8,000-lbs. The 6.5 averaged 10.8-mpg for the ~4.5K mile round trip, running mostly at 70-mph. That truck had 4.10 gearing, and always ran in OD (4L80-E) unless pulling a grade. I wish we'd had your Holset turbo, but it ran with a GM-8. It could pull grades about as well as a similarly loaded stock LB7 Duramax/travel-trailer that traveled with it. Never had a heat issue while pulling grades or on the flat, even though it was pretty warm... i.e. 105F running across South Dakota in late August. You can see pics of the truck/trailer and read more about that trip here: https://www.thedieselpage.com/finale.htm
arveetek
07-09-2023, 14:07
I just turned over 20K on the 'new' engine, and it's been right at 2 years now since the head gasket blew starting this whole project. The whole rig has been running great, no issues at all now. I do have a slight coolant leak (a few drops on the ground periodically), but it appears to be either the radiator or lower radiator hose. I can't see where it's coming from, even with removing the fan shroud and the lower skid plate. It hasn't gotten worse, so I haven't paid a whole lot of attention to it. I fear the next step would be to pull the radiator, and I just haven't been concerned enough to do that just yet.
I quit keeping track of my fuel mileage; I discovered my odometer is not recording mileage correctly. The speedometer is spot on, but when I check the odometer with my GPS app, it's showing a bit slow/behind. The trip odometer quit years ago, so after 395K miles, I guess it's not hard to believe that the main odometer would be a bit worn out by now as well.
The engine starts immediately, in any weather, with very little smoke at startup. I've been on quite a few camping trips now, and she loves to pull hard, and never even gets close to being hot when towing. The old engine ran hot all the time when towing, and I always had to keep one eye glued to the temp gauge. Now I can tow as hard as I want, and not worry one bit. I still plan to swap to 4:10 gears one of these days in order to improve towing performance.
The HX35 turbo works great, but there is quite a bit of turbo lag. The low-stall torque converter combined with 3.42 gears and 33" tires means that I have a lot of black smoke when pulling away from a stop when towing my camper. It takes a bit longer to spool up than the original GM4 I was using before, but the cooler running engine and less backpressure is really worth the trade off. Once it spools up, though, the smoke clears away and she pulls hard. I can barely detect any smoke at all, even at full throttle, so she's burning the fuel quite well at that point. Unless I really push it, boost stays around 10-13 psi on hard pulls. Once in a while it will climb to 15 psi if I really keep my foot in it, but generally that's not needed.
I feel very confident in this rig now, and wouldn't hesitate to jump in and drive to anywhere in the country. I love driving an old school diesel rig, and love getting comments at fuel stations; a majority of folks are surprised to find out that this is, in fact, a factory diesel.
Casey
DieselDavy
07-12-2023, 21:52
That is awesome Casey! Looks good too!
Makes my 131K unit seem like a pup!
Dave
Glad to hear the good news....
Just being anal here.....I would chase down that coolant leak.....Issues rarely happen at a convenient time ....Out on the road is not at all the place to have trouble..
May be just a quick tweak on a hose clamp....Or maybe a leaking water pump seal....
Never know......
arveetek
07-13-2023, 11:36
The leak is from the passenger side under the radiator; it's either the radiator or lower hose. It's just a drop or two periodically, but I agree, I need to get it figured out.
Casey
Casey/arvteek,
I agree with you I get a lot of questions and comments at the fuel stations about my 2005 Jeep Liberty CRD diesel. Yesterday I got some unexpected help while filling up at the diesel pump. The pump was on automatic shut off when full and I was cleaning the windshield when a woung girl pulled up behind me in a PS Ferd and jumped out and shut off the pump. She then came around to the front of the Jeep to tell me how she saved the day. When I told her it was a diesel her face turned so red with embarrassment that it may still be red today. We both got a good laugh out of it and I thanked her for the good intension. It was nice of her to attempt to help a stranger.
jumped out and shut off the pump
Now that's funny!
DmaxMaverick
07-14-2023, 18:54
I have had, twice, a station owner rush out to tell me I can't get fuel at their station. They "didn't need the business from anyone so stupid to pump the wrong gas in their car". I suspect their insurance company put them on notice (I noticed the pump handles, at least at one station, were all the same). The owners weren't born in The 'States. Probably somewhere more east of here. It's also happened to my wife (although, she's pumped the wrong fuel a couple times).
More Power
07-14-2023, 22:29
I just turned over 20K on the 'new' engine, and it's been right at 2 years now since the head gasket blew starting this whole project. The whole rig has been running great, no issues at all now. I do have a slight coolant leak (a few drops on the ground periodically), but it appears to be either the radiator or lower radiator hose. I can't see where it's coming from, even with removing the fan shroud and the lower skid plate. It hasn't gotten worse, so I haven't paid a whole lot of attention to it. I fear the next step would be to pull the radiator, and I just haven't been concerned enough to do that just yet.
I quit keeping track of my fuel mileage; I discovered my odometer is not recording mileage correctly. The speedometer is spot on, but when I check the odometer with my GPS app, it's showing a bit slow/behind. The trip odometer quit years ago, so after 395K miles, I guess it's not hard to believe that the main odometer would be a bit worn out by now as well.
The engine starts immediately, in any weather, with very little smoke at startup. I've been on quite a few camping trips now, and she loves to pull hard, and never even gets close to being hot when towing. The old engine ran hot all the time when towing, and I always had to keep one eye glued to the temp gauge. Now I can tow as hard as I want, and not worry one bit. I still plan to swap to 4:10 gears one of these days in order to improve towing performance.
The HX35 turbo works great, but there is quite a bit of turbo lag. The low-stall torque converter combined with 3.42 gears and 33" tires means that I have a lot of black smoke when pulling away from a stop when towing my camper. It takes a bit longer to spool up than the original GM4 I was using before, but the cooler running engine and less backpressure is really worth the trade off. Once it spools up, though, the smoke clears away and she pulls hard. I can barely detect any smoke at all, even at full throttle, so she's burning the fuel quite well at that point. Unless I really push it, boost stays around 10-13 psi on hard pulls. Once in a while it will climb to 15 psi if I really keep my foot in it, but generally that's not needed.
I feel very confident in this rig now, and wouldn't hesitate to jump in and drive to anywhere in the country. I love driving an old school diesel rig, and love getting comments at fuel stations; a majority of folks are surprised to find out that this is, in fact, a factory diesel.
Casey
Nice update!
It sounds like the HX responds similar to the Banks turbo I had on my 6.2. A little black smoke at the beginning is worth getting a cooler running engine and more power. ;)
Sarah took the Blazer back to her home some 120 miles distant, mostly I-90 traveling. Said she drives about 75 on the interstate. We filled the Blazer's tank just before she left and reset the trip meter. Hoping to get a better handle on fuel economy... though there'll be some town driving on that tank before we check it again.
It's interesting to note that she immediately saw the difference in how the 6.5TD Blazer climbs grades compared to her Malibu. The Blazer didn't downshift on the grade over McDonald's Pass on US-12, where her car always dropped a couple of gears. The wonders of turbochargers and diesel torque! :)
Jim
arveetek
01-12-2024, 12:52
I just got back from a 1,200 mile round trip to French Lick, IN for an RV trade show. I drove my own personal vehicle, since I don't trust any of our company's currently available, high-mileage trucks! Even though the ol' Tahoe has over 405K on the odometer now, I feel perfectly comfortable driving her anywhere.
This is the first time in many years that I've taken the Tahoe on a road trip without a trailer of some sort. I used my GPS app to check my odometer, and currently the odometer is off by 1%, not as much as I thought. But, I was able to set a record high of 18.9 mpg on leg of the trip. That's the highest I ever recorded with the Tahoe.
She ran great for the whole trip with no issues whatsoever. Still running like a champ. I have narrowed down the small coolant leak to my "new" aluminum radiator (which is actually going on 6 years old now), and I'm still debating what to do about that. It didn't leak enough coolant on this trip to warrant topping off the reservoir, but it's still annoying knowing that I have that leak. I've also noticed my power steering gear box is leaking a little fluid, so those are a couple of maintenance items I will need to address eventually.
I've also recently replaced the exhaust with a new, complete 4" system (3" downpipe to 4" after that). It was a tight squeeze, especially near the rear fuel tank. I'm still thinking of tweaking the tail pipe a bit for more clearance by the tank.
I also just installed a Badland Apex 12K winch on the front! It's "hidden" behind the front bumper. I'll try to get pics uploaded soon of all that.
Casey
Glad you had a good trip....
Those pesky little things (Leaks) Can be managed for a while ....But getting them fixed is surely the best plan........
arveetek
04-15-2024, 13:10
My Tahoe currently has a 10 bolt rear axle with 3.42 gears. Last weekend I picked up these jewels:
https://live.staticflickr.com/65535/53656926845_fb80288088_b.jpg
https://live.staticflickr.com/65535/53656926850_6bc3dd58d3_b.jpg
That's a 14 bolt semi float rear axle with 3.73 gears and a G80 locker, and a matching front diff with 3.73 gears. I wanted to go with 4.10 gears, but I didn't really want to put that kind of money into a 10 bolt, as I feel I'm already pushing that axle to the limit when I'm towing my camper or off-roading, and trying to find a 14 bolt semi float in a 6 lug configuration with anything lower than a 3.73 ratio is next to impossible to find, so this will be a good compromise in gearing and strength.
I am in the process of cleaning up the axle, and will be installing new wheel cylinders and steel brake lines for good measure. Thankfully the rest of the brake components look really good.
I will be installing new rear leaf springs and Bilstein shocks while I'm at it, since after 400K miles, the rear springs are sagging real bad.
I'm looking forward to finally getting some lower gears! With my current 33" tires, this will get me back to just slightly lower gearing than a stock setup.
Casey
a5150nut
04-16-2024, 11:42
Casey Timbrin bump stops would be a nice add while your in that far
arveetek
04-16-2024, 11:47
Casey Timbrin bump stops would be a nice add while your in that far
I currently have RAS (Road Active Suspension) helper springs:
https://activesuspension.com/
I have them cranked to full max, but the original springs are so flattened out, they weren't helping as much as possible!
The Timbrens look nice, but I've about maxed out my allowance, so I got stop the spending somewhere! :D
Casey
The 14 bolt is a good addition for sure.
The little 10 bolt is pretty sketchy if you start reefing on things
More Power
04-17-2024, 08:35
Good score Casey.
I'm thinking about putting Lil Red's rear disc brake conversion articles back online. I used the very same rear axle in Lil Red that you have here. The articles have the drawings for the brackets along with the part numbers for the OE GM brake parts (2003 K1500).
arveetek
04-17-2024, 12:03
Good score Casey.
I'm thinking about putting Lil Red's rear disc brake conversion articles back online. I used the very same rear axle in Lil Red that you have here. The articles have the drawings for the brackets along with the part numbers for the OE GM brake parts (2003 K1500).
I would be interested in reading those! I wouldn't mind upgrading to disc brakes in the future.
Casey
The 4 wheel disc is nice.
Our 2005 Burb K1500 has 4 wheel disc....A panic stop and that rig just squats....
Some previous owner put 20" wheels with the low profile tires on the thing.....
I have not been a fan of the ultra low profile tires on the big wheels...Funky looking....
275/55x20
Rig handles extremely well....No roll in the corners......
The 4 x disc is definitely a good thing......
More Power
04-24-2024, 18:36
I would be interested in reading those! I wouldn't mind upgrading to disc brakes in the future.
Casey
Here they are!
https://www.thedieselpageforums.com/tdpforum/showthread.php?35210-Lil-Red-Duramax-6600-Allison-1000-Conversion-amp-OBS-NBS-Dash-Conversion&p=336711#post336711
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