6.5 T Replacement

[Basshopper]

I may have to replace my 6.5 again, did it at 125K and 100K later losing coolant and some steam coming out of the dip stick. Does anyone have a recommendation on a replacement motor that would be more bullit proof on the block and does not break the bank. The last one cost me $8000 installed new from GM and doing this every 100K miles is not my idea of a good time.

thanks for your help

[Artworks]

I am fairly new here, but with my own experiance of having my 6.5 crack block & head at 200,000 kl (120,000 miles ) and many other 6.5 owners the same, has enyone looked at holding GM responsible for not fixing the problem? I can understand that the first couple years being a problem, but by 1999, you would think this would be solved. I know that going after a big Company is hard, but it's cost a lot of people a lot of $$$$, and there are good solutions out there, and we, consumers should not have to put up with poor products and service. Every 6.5 owner should be getting, at least some support from GM, and not have to rely on chasing solutions here.

[JoeyD]

http://www.dieselservices.com/
http://www.kennedydiesel.com/
Both offer better 6.5's with durablity built in as well as power.

[ronniejoe]

I've considered a business venture of building splayed main 6.5's for people like the one I built for me (see the articles in my signature). If I do this, I will ask Jim to remove me from the moderator status to avoid conflicts of interest. The problem is, I doubt that most people will really want to pay for it. As a rough estimate, $8,000 to $10,000 would get you a fully blueprinted and balanced engine with splayed mains and 18:1 compression. Optional, extra cost items could include a performance turbocharger. I don't think there is a better solution out there (including Cummins conversions), but it does not come cheaply.

[JoeyD]

I've considered a business venture of building splayed main 6.5's for people like the one I built for me (see the articles in my signature). If I do this, I will ask Jim to remove me from the moderator status to avoid conflicts of interest. The problem is, I doubt that most people will really want to pay for it. As a rough estimate, $8,000 to $10,000 would get you a fully blueprinted and balanced engine with splayed mains and 18:1 compression. Optional, extra cost items could include a performance turbocharger. .

This would be a brand new motor with all new internals? Not a bad a price.


I don't think there is a better solution out there (including Cummins conversions), but it does not come cheaply..

Depends on what you want to end up with. If it's huge power or even longevity the Cummins would be a better option. I would guess you would be at $15,000 for an Auto world install including motor and it would be an 03 and up common rail motor. They have new motors for a great price.

[Basshopper]

I've considered a business venture of building splayed main 6.5's for people like the one I built for me (see the articles in my signature). If I do this, I will ask Jim to remove me from the moderator status to avoid conflicts of interest. The problem is, I doubt that most people will really want to pay for it. As a rough estimate, $8,000 to $10,000 would get you a fully blueprinted and balanced engine with splayed mains and 18:1 compression. Optional, extra cost items could include a performance turbocharger. I don't think there is a better solution out there (including Cummins conversions), but it does not come cheaply.

Would yours be the same as a pensula motor? any thoughts on that your price is in their ballpark so you are not out of line, I have not had a change yet to verify my problem as I am in CA fishing a bass tx it maybe just a leak somewhere else.l want to get an oil sample that will tell me if coolant is present and as we say the rest will be a new motor.

[ronniejoe]

The peninsular engines are not blueprinted or balanced (IIRC) and do not have splayed mains. They are using the new GEP block and heads which is a good thing.

[Basshopper]

Had my engine checked out and the mechanic does not think thier is water in the oil was just some blow by,possible stuck (PCV valve not sure thats the correct name its the orignal one 210K miles) I am going to verify this week when The oil gets changed and send in an oil sample for testing. Assumming no water, with a 100k on this motor is it too late to install a stud girdle and if not where would I get one. I am sure until you pull the pan and inspect, one really never knows until then.

[farmerherb]

I know a fellow in Waynesboro Pa. that sells a rebuilt, balanced 6.5 for 3800.00, installed around 5000.00. He always has two or three trucks waiting to be rebuilt. I bought a 6.2 from him 12 years ago put 248,000 on it broke a piston skirt put another piston in still running.

[Basshopper]

Had my engine checked out and the mechanic does not think thier is water in the oil was just some blow by,possible stuck (PCV valve not sure thats the correct name its the orignal one 210K miles) I am going to verify this week when The oil gets changed and send in an oil sample for testing. Assumming no water, with a 100k on this motor is it too late to install a stud girdle and if not where would I get one. I am sure until you pull the pan and inspect, one really never knows until then.


ronniejoe Do you have any thoughts on this??? Thanks

[ronniejoe]

The vapors from the dipstick tube are probably caused by blow by. However, if the Crankcase Depression Regulator (CDR) valve is functional, this is not a good sign.

The other question to answer is where is the coolant going? Have you checked for bubbles in the surge tank?

I have very little confidence in the stud girdles that I've seen. I doubt that they will do much at all to stiffen the bottom end.

Just my opinion.

[BobND]

However, if the Crankcase Depression Regulator (CDR) valve is functional, this is not a good sign.

Factually, now, has anyone on here really seen a CDR valve fail, besides leaking oil externally, through the tiny vent hole in the cover, from a failed diaphragm?

There are guys touting CDR valves on ebay, saying repalcing your CDR will cut oil consumption.

Yet, the way I see the CDR valve, it is simply always wide open, except if the air filter gets restricted, or some other intake restriction occurs. Then, it partially, or totally closes off the passage to the intake or turbo, preventing too much suction on the engine's innards.

It does not control the loss of oil (in the vapor that flows out with the engine "blowby" of combustion products), it simply prevents the crankcase from being evacuated into the negative pressure range, should the air intake be restricted.

I just changed an older 6.2 over to a 6.5 RH valvecover and newer CDR valve to get rid of the leaky plumbing mess from the oil filler tube to the CDR valve behind the alternator, to both sides of the intake.

The 6.5 RH valvecover makes an attempt to separate oil from the blowby stream by flowing it through wire mesh before it enters the CDR. Those of us with 6.5 TD's with some miles on them know how effective this oil separation from the blowby stream is everytime we look at our oily turbo, or intake hose connections!

I have 4 CDR valves of various styles lying on the bench, and all are made the same... totally open inside,no mesh or anything, just a diaphragm with a plate in the center, with a spring holding the diapragm and plate away from blocking the internal passage from the crankcase side to the intake side.

The only ways I can see these failing is the oil leak to the outside, through the diaphragm, which I have seen, or the spring breaking (highly unlikely, I think), or simply being so full of crud that combustion products are blocked from passing through to the intake, which would tend to make for elevated crankcase pressure, that would end to blow oil out past seals and gaskets.

Is this reasonable, or do some of you guys see another way a CRD valve could "cause high oil consumption"?

Has anyone seen a CDR that was significantly clogged or internally restricted?

[JohnC]

I think that the CDR as a rule is always limiting the suction applied to the crankcase. When it fails way too much air is pulled through, causing oil to be drawn into the intake in excessive quantities as well as pulling unfiltered air past the seal lips.

[Basshopper]

Had my oil tested and YUP its got Glycol in the oil tested high for Sodium and Potassium both indicators. So the big question know, could it be heads only or how do I find out the cause with out tearing it all down, its my only vehicle, or do it go buy a duramax and move on??? Any next steps suggestions would be helpful at this point,. Thanks

[john8662]

Judging from the common occurance of cracked blocks from 97+ I'd venture to say that the coolant is entering through a cracked block and mixing with the oil. Because this is a replacement engine, I'll also be interested to find out if this is an "enhanced block" or old stock...

A compression test will indicate whether you have a head gasket leak or not. If you've got a head gasket leak, then there is a possibility for coolant to enter the crankcase, but not as likely.

The vapor you're seeing probably isn't steam, but rather blowby gasses from the combustion process.

The point to make about blowby is whether or not the amount present is acceptable or not. Getting enough blowby to have a vapor escape both the oil filler tube and the dipstick is getting to the excessive stage. A slight haze out of the oil filler tube at idle isn't necessarily a shot engine, it's the huge stream of blowby out of the filler that's concerning, paired with smoke out of the dipstick.

I'll also agree with Bob about the CDR, I don't think that oil consumption is normally due to this device. Now, if other symptoms exist like leaking gaskets, front and rear main seals leaking, then yes, I'd say that the valve is suspect and may be sticking closed, causing seals to not do their job.

[afgunn]

BobND,
I agree with you totally and completely! The CDR confused the H*** out of me until I slept on it (not literally). It definitely does not work like a PCV valve. I almost bought a new one too until I had thought on it more. The amount of tension the spring has on it can only mean it would "regulate" or "block" the suction when the air filter/intake is totally blocked - or almost totally! At idle there is ONLY 0.5 to 1.0"WC of vacuum (1"WC = 0.5psia). At 2000RPM there is only about 4.0 to 6.0"WC (2 to 3psia) of vacuum. After all, this "vacuum" is created from the intake after the air filter and before the turbo! With the tension of the spring, there is no way ANY "regulation" is occurring under normal conditions. You cannot feel the vacuum with your finger at idle. Not sure about at 2000RPM.

[AC Bingel]

The peninsular engines are not blueprinted or balanced (IIRC) and do not have splayed mains. They are using the new GEP block and heads which is a good thing.

I think Peninsular is the way to go. I love mine! Matt at Peninsular doesn't think splayed mains are necessary with the GEP block and 18:1. $6500 is not a bad price either.

[Basshopper]

Just to clarify this post thought it was long gone, The test for water was faulty, since I burn WVO it has the same ingrediants as the Coolant Sodium and Potassium. I have driven 20K miles since this happened and have not used any coolant. Had another test that tests for petroleum products in the coolant and it was negative. So all is well. Acutually sold the burb last week and driving my new D Max. Thanks for all your help on this.

[DA BIG ONE]

I've read that the CDR should be changed out @ 30,000 miles no matter what to avoid oil consumption through intake. So, what does the factory manual say about it, or how about the military manual's?

[DmaxMaverick]

I've read that the CDR should be changed out @ 30,000 miles no matter what to avoid oil consumption through intake. So, what does the factory manual say about it, or how about the military manual's?
The manual states nothing about a fixed replacement period. Only diagnostic procedures for excessive oil consumption or leakage. There is a mention of an inspection and test for VIN Y engines (96/97) at 60K, but it doesn't apply to a 6.5.

The function of the CDR is to prevent excessive crankcase vacuum. It will not regulate positive pressure. You can test operation of the CDR with a manometer. As long as the WC (Water Column) does not exceed 4" at 2000 RPM's (no load), the CDR is functioning normally. The CDR is normally open, and only closes when crankcase vacuum aproaches 4" WC. Crankcase pressure should have no effect on the CDR (you have other issues if you have pressure). The normal crankcase vacuum range is 0" to 1" at idle, and 0" to 4" at 2000 RPM's, no load, but under no circumstances should it exceed 4". If vacuum never exceeds 4", the CDR is operating normally. If vacuum exceeds 4", the CDR needs replacement. If your engine has excessive blowby, it will skew the CDR test results. In that case, a loaded test (max boost PSI at governed RPM) needs to be done, up to governed RPM. Still, the vacuum should not exceed 4" WC.