Recent 6.5 rebuild problems

[gregretter]

I'm wondering if I can get some input from some people with more experience than I.

Just finished a rebuild job on my 1996 Chevy 4x4 K3500 Ext Cab 6.5 turbo diesel. This is my 1st engine rebuild experience but had a lot of help. Now that its finished and back in the truck and running, we have an issue that we cannot track down. It is a ticking sound, sort of missing out, with lots of white smoke. We are pretty sure it's fuel related. It makes your eyes water.

Little history on the rebuild. The reason I had to do it was it spun a rod bearing. For the most part, this is all we found wrong with the engine. I had the block, heads, pistons and rods all checked and reworked where needed. Got a different crank that was turned .010. The one rod that had the spun bearing was reworked and everything was plastigaged as it went back with all proper torque specs, per this site. Both heads had the tell tale cracks on each end between the valves. One had 1 very small spider like crack on each end and it was decided that we would reuse this head. The other head had the same cracks but one went pretty deep down into the valve guide itself. We did not reuse this one. I ordered a newly complete remanned head from cylinder heads international in Texas. It looked like an excellent reman job on this new head. I reused the same pistons(the machine shop said they were still good and I wouldn't spend the money on new) and just put on a new set of rings. New oil pump, water pump with new 180 degree thermostat, newly remanned injection pump, new remanned injectors, new crankshaft position sensor, oil/fuel pressure switch, yada yada, blah blah blah.

The engine starts immediately, very well, but smokes white bad enough with the stock #5 resistor installed in the pmd which is mounted on an FSD from SSdiesel on the drivers side top of the intake. It smokes even worse with the new #9 resistor. Had a certified mechanic from chevrolet hook up the computer, clear the codes and time the pump. It is in time. According to him, it is about "as good as you can get it". He stated we had it almost dead on ourselves. Can't tell you the exact number. As he was trying to find out what this ticking or knocking sound was, which he felt was fuel related also, he went through each cylinder and shut them down with the computer. They all shut down and missed the same except for #4 which didn't seem to quite miss out completely, so he said I would start by checking that injector. Did that today along with the 2 cylinders that fire ahead and after cylinder #4. Had a diesel shop check #4 injector, which they said was fine. I took out the other 2 injectors and tried them both in my 94 Chevy 6.5 with no apparent problems.

It almost sounds like a rod knocking but several other opinions say it is not. It carries awesome oil pressure, loses no water, and has about 85 mile on it currently. Power is lower than it should be. After we had the mechanic check it with the computer and time it, I really got into it on the way home thinking that if it's a rod, I'm gonna find out. The power seemed basically to be there but got worse the longer I pushed it and the closer I got to home. I couldn't hardly get it over 55mph. It just falls on it's face. It is more definite now and has less power than when we 1st got it running, but still has great oil pressure and no coolant loss. No compression check has been done yet but that is basically our next step. Listening to the motor, it sounds like it is coming from the passenger side of the engine. We had the valve cover back off tonite on that side and everything appeared fine. Getting great boost from the turbo also. Lift pump appears fine also. It is the same one that's been on it since I've owned the truck which I purchased with 32000 miles. I have a new AC Delco to install but haven't done it yet because the old one appears fine. I turned the t-handle while it was running about 2 turns and fuel come out. Don't know if it's the right pressure for sure, but I can hear the pump run and it is pumping fuel. It's seems like the engine is getting way plenty fuel! I also should make it known the the truck has sit for over a year due to not having the money. The old fuel that was still in the tank has all been run thru it and more new has been added. I also rechecked the new fuel filter tonite and it still looks new.

Anyone have any ideas what we've done wrong?

I would really appreciate any help that could be provided.

We are at our wits end on what to do and are basically ready to give up and take it in to the diesel mechanic and spend whatever to get it figured out.

Thank you

Greg

[Dvldog 8793]

howdy
Sounds to me like you have a dead cylinder. The White smoke is unburned fuel/air from one of your cylinders. Possibly a valve hanging up? I had an identical sound when I had a bad injector. Also had smoke with the knocking but it only did it occasionally. First time it happened I was in town and scared the s**t out of me! I killed the motor and coasted into a parking lot. Started it back up and it knocked for about 2 minutes and then went away. I replaced the pump and injectors shortly after that and never experienced the problem again. I would do a compression test and I think that will tell you what your problem is.
Good luck!
L8r
Conley

[eracers999]

The timing info is too vague, setting the pump timing is a 2 part process. Pump or timing set/learn, TDC offset learn. If yo u paid a dealer to set the timing then he should be able to tell you exactly where everything is. Sounds like you dont have the stepper motor hooked up on the pump. Or whoever told you the timing is as good as you can get has no idea where it is either. Hope you find out, best of luck.

Kent

[twaddle]

Hi there,
Have you tried another (good) injector in No 4?
I would also suggest a compression test to No 4,
make sure the engine is warm.

When the engine is running you could check the ex manifold at the port flanges to compare temperatures.
A cylinder with bad comp or a bad injector will usually have a difference in temperature to the others.

Good luck,

Jim Twaddle
Biggar, Scotland.

[gregretter]

Thank you so much for all the input so far. We are going to do the compression check next. We are trying to get time to do it this weekend sometime. I will let you know what we find out. I'm leaning towards a head gasket or a valve issue right now. It is not losing any water to speak of but the low coolant light displayed for a short time on the way home from the chevrolet mechanic. I don't know why this would have come on when it has a good water level. This is just so frustrating. I've got about $3200 in this thing so far.

[Dvldog 8793]

Howdy
Good info on the temp method to determine what hole is bad. An ifrared heat gun can tell you allot about what's going on in your engine. Also if you suspect water loss then you might want to let it sit for a while after you run it and VERY slowly crack the oil drain and wait for the fisrt drip to come out, hopefully it will be oil. If you have a head gasket I would expect that you would have some other symptom. I think I would lean toward a valve issue.......
Have fun!

BTW When I replaced my motor(cracked block) I think all total was about 7grand!

L8r
Conley

[Jim P]

Someone else on this forum had a knock after a rebuild and it turned out to be 2 crossed injector lines on the pump. If they are crossed, one of cylinders will fire early causing the knock and the other will fire late causing the smoke. This will definitely kill the power.

Double check those injector lines.

[john8662]

Lifters can also cause valve issues. My lifter problems in a 6.2 have led to white smoke at idle and being gutless off the line, but once turning some RPM it runs ok. I also have the ticking at idle and noticeable at 1k-1.5K RPM. My problem thus far is lifters NOT pumping up, and staying pressured up. Maybe you're having the same issue? This problem has been with NEW lifters, of different makes.

What you can do to check is remove the valve covers (not fun) and get each cylinder to TDC or where both valves are closed and not about to open. Then press down on each of the rockers (pushrod side) until you find a loose one. You'll want to be able to rotate the engine over to do this. The best way is to remove the crank pulley and rotate the engine by using a socket on the harmonic balancer bolt. The loose ones will be lifters that didn't pump up.

[ 05-28-2005, 02:56 PM: Message edited by: john8662 ]

[gregretter]

How can I double check the injector lines? Is there a diagram somewhere I can refer to? When we reinstalled the lines(they are preformed of course) There seemed to be only 1 way they lined up, so that is the way we hooked them back up to the pump. How are the fuel outlets on the pump numbered?

Thanks for all the good info thus far!

[turbovair]

I recall that very post. The injector lines were crossed at the pump connections.Check the lines based on cylinder firing order. If they were all backwards, I dont believe the engine would run at all, so a couple could be switched.Good advice!

[gregretter]

Well, we were going to check the injector lines eventually but thanks to Jim P and Turbovair's posts we decided to do it last night. You guys were right. We had 4 and 5 switched at the pump. I didn't think this was possible but they seem to be the 2 easiest to get wrong if your not careful. It made alot of sense with the way the engine was acting. Hopefully get it back together tonite and all is well. If this takes care of it, thanks so much for all your input. We feel like total idiots.

Trace your lines prior to reassembly!!!!!!!!!!!!

[mhagie]

That was my truck that had the injector lines crossed they were #7&8 the ones on top.
I can't remember but I believe it was Jim P that gave me the idea to check and he was correct.
Truck a lot better with 8 cyls instead of 6+. :D
because 7&8 fire next to each other it idled fine but as soon as you stepped on it a tad it would knock.
Merle

[Jim P]

I would have bet money that that was the problem.

I'm glad I could help and happy you got it fixed.

[gregretter]

Thanks Jim P. Got her all back together last night and she runs like a scalded dog. I love it!

This site has been so helpful through this whole process. Thanks to everyone!!

[ejk2352]

Jim P. I live in Salem, Ohio. Shoot me an e-mail ejk2560@hotmail.com