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Looks like i have a problem

They are hard to see but that's where they where leaking

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Sent from my SM-G930V using Tapatalk
 
Im person i can barely make them out but he pressure checked them and they were leaking

Sent from my SM-G930V using Tapatalk
 
That was GM's solution...

That is a weird spot to Crack. Has to be a defect in the casting that took a while to fully develope. The valve train was completely stock, only exception would be the .010 head gaskets and that may have lessened the open valve spring pressures.

Your luck is mud like.
 
I can't tell from the pics but are both spring pads the same height?? One should be taller than the other, the pics look like the pads have been re-cut at some point??
 
You need to get ahold of clearwater. Send them the pics- links to the thread if nothing else. I know they are going to say -casting error from GM and we are not liable- We just reman it. All the same if they wont bother examining the failure after that low of miles- it speaks volumes to me.

If they do look into it- at least they are handling a low mileage failure with concern.

That is an interesting place for failure...
 
Will L. said:
Yesterday I was at a store and saw a guy fighting with a liftgate on his truck. I walk up and asked if I could show him an easier trick I learned. He said a line we've all heard before "I've been doing this 20 years." To which my favorite response is usually "You've been doing it WRONG for 20 years mother f****r !!!" To him, since he was polite, I skipped the last 2 "non church words". Then I said let me show you- now his job will be easier time he uses it.

I have always held to the thought of keep the pressure high, and need less turbo. As I read your last point and think to myself, yes that works, but if you just kept the pressure up like I have for the last 20 years...Then I hear my son in the other room laughing as he repeats the words I said to his friend telling the story.

It takes hearing my own words at the right time sometimes to consider. Have I been doing it wrong for the last 20 years?:nailbiting:

I am very reluctant to give up the power in compression. I know I don't want to for the hummer until I can fit a real turbo and compensate. Are there builds done still running a gm6 with higher boost numbers and maybe a wicked wheel that can compensate the loss?

I am going to print out the charts you posted and study them till more clicks in my head. I have great concearns about worn rings dropping compression on already lowered compression and hard starting. I get when everything is new it will fire easy. But once there is 150,000 milesor more on it...??

My mercedes diesel is the great 6 cylinder that has 22:1, the only one touted as a better long life is the 5 cylinder om617 which has 21.1:1. I know different designs on many things, but the same idi, piton top, injector style, precup style, crank to rod/piston weight ratio,bore to stroke ratio,... basically Detroit/GM copied all the key factors from the 1970's Mercedes Benz design table and made it a v8 for GM to work off of. Then GM made multiple key changes, all of which are the problems we all know of today. Idk, have the MB guys learned to drop there compression also? Some reading in my future.

I am trying to accept what you are saying, but hard to swallow this pill. A more open mind is going to read on and try to find old 6.5 info... please continue to share:wideyed:
Click to expand...

With compression look at it this way. The higher the compression, the easier the engine will start in cold temperatures and more efficient for a NATURALLY aspirated diesel. Once forced induction is added a lower compression ratio becomes necessary for longer engine life, more power, and more efficiency.

Compression ratio in diesel engines ranges from 13:1 up to 22:1 (that I know of, been working as a heavy diesel mechanic for the past few years). Most of the heavy duty engines from CAT, Cummins, Detroit, etc run in the 13-16:1 range. With forced induction the lower compression ratio wins in every category. Less stress on the combustion chamber, more efficient burn of the fuel leading to more power and cleaner emissions, etc.
 
sctrailrider said:
No, the lower comp doesn't hurt anything, it helps everything, what does it take to make power... air & fuel.. the more you have of each the more power you have ... fact... less stress on the entire system, including back pressure, the added volume needs a p;ace to do it's work...

Ever wonder why the big 3 diesel makers dropped their ratio's ?? You can only force so much air & fuel into a given space, give a little more space and ya gain more...

I couldn't see any difference starting in cold temps, I think most have the impression dropping the compression causes lots of trouble when it just isn't true, all hear say....

I can say this as a fact, with the stock compression if ya add a bigger turbo, add more fuel, sooner or later things will break, this isn't a motor that can take that in stock form, and don't think head studs is the cure either, it's just a band aid, the stress will find a way out...
Click to expand...

I built my 6.5 with Mahle Marine 18:1 pistons back in 2007 - block needed decked a bit a get flat/straight. If memory serves, comp ratio came out around 19:1. It did have some impact on starting below say 10 degrees F, but I compensated with longer glow time, faster starting rpm via Powermaster starter, better batteries, cables, etc. Any negative impact on mpg doesn't seem a deal-breaker as my truck will do 18-20 mpg highway at 65 mph (285/75-16's (33" tire) 3.73 gears, NV4500).

Agree with sctrailrider that comp ratio is a key factor if you're gonna work a non-P400 6.5 hard and expect durability/longevity at higher than stock hp levels. Built mine in 2007 and still in good shape a decade later - and it's pulled my 26' GN a lot of miles - well above the GVWR the GM ever intended. Heat management also gotta be addressed: lower turbo drive pressure, ECT kept under control, and lowering charge air temps helps durability.

Imagine a P400 ups the engineering limits considerably and then the theoretically better for IDI design higher comp ratio make sense. Guessing that Mercedes built a tougher IDI block, crank, & heads than GM's 6.5?

In 2007, I had to work within the durability limits of GM's block, crank, & heads. After a decade, I'm happy with my 19:1 6.5. If it hadn't gone the distance, I wouldn't be.
 
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Yeah, the Mercedes is built with top notch metalurgy, and like most things they build, all is well designed, or quickly altered when mistakes are found. They do have a lower boost level with higher volume turbos compared to other engines their size- imagine that, same thing we all learned. T3 flange on 3.0 liter engine, t25 on the tiny 2.5 liter for some, others a t3.

I forget boost for the smaller, but 3.0 liter is 13psi iirc.

This old dog is trying hard to learn to sit...
 
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