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Did a number on them pushrods lol.
 

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No I saw the crank too. Them breaking dont surprise me anymore lol if the rods are straight and pistons look good I may know someone who wants them.
 

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So i saw where the OP said he was on tow tune for trans re-learn, but were you just letting this thing eat in tow tune or what? This Seems to be a little much for just being in a tow tune daily driving or towing with some sense.
 

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Cody, its probabaly Mr. Epa certifieds tuning :stickpoke. Cranks can snap idling, cruising down the highway, whatever.
 

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Cody, its probabaly Mr. Epa certifieds tuning :stickpoke. Cranks can snap idling, cruising down the highway, whatever.
Nic I appreciate you giving me nightmares for the rest of the week lmao :ninfa
 

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Do some reading on these engines and their crank issues.
 

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=====================================

I find it difficult to believe that engines with a history, down thru the years, of outstanding reliability (as is the case with our Duramax's of various series) absent abuse, meaning trying to draw significantly more power out of them then the stock "rating", will incur this kind of failure.

I have worked on and around all manner of internal combustion engines (probably a bit more than any of you in here). I have yet to see an engine do what this one did absent major abuse.

Bottom line - those of you with stock engines, and those of us who have a "tune" to take advantage of our "deletes" (but are conservative in the use of the additional power) do not have anything to worry about.


If you read enough on this forum you will see that this is in fact quite true. The duramax engine has a long history of breaking cranks at that location. This is so much of a common issue that people have created cam shafts with altered firing orders to try to remove the stress from that point on the crank. Plenty of stock trucks have broken cranks like this. There is also a track record of sheering the key out of the crank and cam as well which results in valve and piston collisions.

The Duramax engine is an exceptional engine, but it is also far from perfect. There are plenty of issues with it from the beginning of the series, most have been corrected by this point but the crank issue as far as i am aware has never been addressed by GM. It is not a huge issue, as failures are rare, but there is still a clear history of failures going back to the 01 trucks. The issues with head gaskets, injectors, cp4, are all significantly more common issues though, so that is mostly what you see / hear about.

There are also people making well over 1K HP on a stock crank with no failures, and others who break them on stock trucks. There seems to be little rhyme or reason as to why. Perhaps its a heat treating issue, maybe there's multiple production locations and one is slight harder, who knows, but this does happen.
 

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If you read enough on this forum you will see that this is in fact quite true. The duramax engine has a long history of breaking cranks at that location. This is so much of a common issue that people have created cam shafts with altered firing orders to try to remove the stress from that point on the crank. Plenty of stock trucks have broken cranks like this. There is also a track record of sheering the key out of the crank and cam as well which results in valve and piston collisions.

The Duramax engine is an exceptional engine, but it is also far from perfect. There are plenty of issues with it from the beginning of the series, most have been corrected by this point but the crank issue as far as i am aware has never been addressed by GM. It is not a huge issue, as failures are rare, but there is still a clear history of failures going back to the 01 trucks. The issues with head gaskets, injectors, cp4, are all significantly more common issues though, so that is mostly what you see / hear about.

There are also people making well over 1K HP on a stock crank with no failures, and others who break them on stock trucks. There seems to be little rhyme or reason as to why. Perhaps its a heat treating issue, maybe there's multiple production locations and one is slight harder, who knows, but this does happen.
Agreed!!
From 01 to 16 these trucks break cranks on, stock or 2000hp, babied or abused, low mileage or high. Doesnt matter. Hit or miss. Unfortunately the af cams have proven not to be the fix all eveyone thought they'd be. Plenty of guys have broken cranks with those also. Callie or SoCal billet holy water blessed narrow rod journal crank are the new fix all. We will see how they hold up. If I was building one of these engines I'd skip the 5k dollar fancy crank put a good tested one in with the cam of your choice, af or not, and hope for the best. I wouldnt say it's a super common issue but it happens more than people think.
 

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Agreed!!
From 01 to 16 these trucks break cranks on, stock or 2000hp, babied or abused, low mileage or high. Doesnt matter. Hit or miss. Unfortunately the af cams have proven not to be the fix all eveyone thought they'd be. Plenty of guys have broken cranks with those also. Callie or SoCal billet holy water blessed narrow rod journal crank are the new fix all. We will see how they hold up. If I was building one of these engines I'd skip the 5k dollar fancy crank put a good tested one in with the cam of your choice, af or not, and hope for the best. I wouldnt say it's a super common issue but it happens more than people think.
yea, i probably should have clarified that better. It is common in that there are consistently a few reports every year of it occurring, but it does not make up a statistically large percentage of overall failures.
 

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A good friend had a 20k dollar engine trashed cause of crank failure with less than 5k miles on it. Now his truck is sitting until he can afford to put a stock short block in it cause he cant afford to build it twice. That's actually part of the reason I decided to build a cummins. I have bad luck and didnt want to stick the rods and pistons in my botton end to have the crank snap sometime later.
 

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These scientific thesis statements are truly something special. Nic you cant post in this thread anymore since you don't use your truck as a truck & "haul things". SMH
 

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Wow... the poor op's thread. Hijacked by this^

Silvergorilla is one of the most knowledgeable, no b.s. members on here. He offered relevant advice to the thread. This is ridiculous.

Could we all be trolled on an epic level lol
 

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He is the only person in my ignore list. I just couldn鈥檛 take it anymore.
There was another guy that was really close, but he got banned recently.
 

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Hmmm - let's see 鈥..I bought a truck to use as a truck - as in "hauling things". I bought a truck to use as a truck in both settled and rural areas - translation - far from prompt help.

I learned from this forum - page after page -literally HUNDREDS of pages of sad stories about the CP4 causing in the area of ten grand for repairs.

Solveable problem - about three grand later, thanks to the recommendations I found in this forum, I now have a CP3 - which, I am told, pretty much eliminates the chance of a sudden breakdown.

I found out from this forum that incurring failures, unanticipated break-downs, etc... from the pollution system, leaving one stranded, is not unusual.

Solveable problem - thanks to the recommendations I found in this forum, about three grand later, and my CAT, EGR, DPF safely stored away, I am told pretty much eliminates that problem ( have to admit I couldn't believe until I "got there" how right these guys in here were about doing a "delete").

Now I read (breaking of crankshafts) is "so much a common issue people have (come up with various "fixes" ) "....鈥"clear history never addressed by GM".

Wonder what a properly "built" long block would cost, and how much to swap out my present motor.....?

I read somewhere that GM truck sales are way off in recent years. I did not know I was buying a "do-it-yourself" kit.

Next time this truck fails to do the job it was bought for, it gets "parted out" - not spending one more dime trying to re-engineer it. My next truck will be a Toyota ! Assuming the reported rapid decline in sales of GM trucks is accurate, I am not the only one !


i would really not worry about it. its going to happen, or its not, and theres really nothing that can be done about it besides MASSIVE investments in the engine. The failure rate of cranks is significantly lower than the already low failure rate of CP4 pumps. Perhaps i should have been more careful in what i said, so let me try it again.

The crank shaft cracking at that location has been a historically documented failure mode of the duramax engine since 01 when the block was first put into use in GM vehicles. While this failure does not happen often by large, there are enough occurrences of this failure that is shows a history of this failure being possible on every duramax engine built to date, with the possible exception of the L5P because i do not know if it uses the same crank. Your chances of this failure are very low on a stock or even mildly tuned truck, and i do mean very low. You have significantly higher chances of most other things breaking before the crank does based on the number of reported failures and the number of trucks on the road. This problem becomes more common though as the load on the pistons increases, so when your making a ton of power with your twin turbo kit your chances of failure go up a good bit, but even then, are still not that high. Please do not loose sleep over this, or build a 30K engine, it is not necessary. the 5 failures a year or whatever shows up on this forum is not worth it.
 

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i would really not worry about it. its going to happen, or its not, and theres really nothing that can be done about it besides MASSIVE investments in the engine. The failure rate of cranks is significantly lower than the already low failure rate of CP4 pumps. Perhaps i should have been more careful in what i said, so let me try it again.

The crank shaft cracking at that location has been a historically documented failure mode of the duramax engine since 01 when the block was first put into use in GM vehicles. While this failure does not happen often by large, there are enough occurrences of this failure that is shows a history of this failure being possible on every duramax engine built to date, with the possible exception of the L5P because i do not know if it uses the same crank. Your chances of this failure are very low on a stock or even mildly tuned truck, and i do mean very low. You have significantly higher chances of most other things breaking before the crank does based on the number of reported failures and the number of trucks on the road. This problem becomes more common though as the load on the pistons increases, so when your making a ton of power with your twin turbo kit your chances of failure go up a good bit, but even then, are still not that high. Please do not loose sleep over this, or build a 30K engine, it is not necessary. the 5 failures a year or whatever shows up on this forum is not worth it.
I haven't heard of any major engine failures with the L5P motor yet and there are some people pushing them hard. If the L5P internals prove to be better than the existing would there be the option to use the internals of the L5P for a budget motor build for previous years?
 

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I haven't heard of any major engine failures with the L5P motor yet and there are some people pushing them hard. If the L5P internals prove to be better than the existing would there be the option to use the internals of the L5P for a budget motor build for previous years?
that would probably be a question better answered by silver or someone else. i know very little bout the L5P so im not sure. My guess would be that it would not interchange well due to the new fuel system on it but i could be wrong.
 

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Cody it would probabaly take some machining of various items in the bottom. I haven't followed the l5p too closely but I'd give it a while and see how they continue to hold up. Budget build would be cut lb7 lly pistons and some carrillos or lbz rods if you want to go real cheap. Also just read/talked about 2 of the callies billet narrow rod journal cranks that broke.
Just drive the truck. If it cracks a piston, bends a rod, breaks the crank, injectors fail, lifts the heads, whatever, just fix it and go on with life. Shit happens, everything breaks nothing is perfect. Every engine ever created has some type of weakness or small flaw.
 

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Wow... the poor op's thread. Hijacked by this^

Silvergorilla is one of the most knowledgeable, no b.s. members on here. He offered relevant advice to the thread. This is ridiculous.

Could we all be trolled on an epic level lol
I feel bad for him too. This guy uses every thread to repeat the same story over and over.
 
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