12 lml duramax needs head gaskets

brad6

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Got the news today, $7600 quoted at GM. Truck is about to roll over the 250km mark. I'm on the fence about fixing or dumping it, don't really need the diesel anymore. No payments is nice. Would you guys have the dealer do the repairs or a diesel shop? I have confidence in dealer and have a good relationship with them. Anyone been down this road before? Better off to suck it up or look for something different?
 

CJD

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If it were me I would do it myself. If that is not an option I would definitely get another price from a diesel shop rather then the dealership. They will be charging top dollar for sure.
 

pfi572

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$7600 I believe is a pretty fair price as it’s a lot of work .
Upgrade the head bolts and anything else that will improve longevity while your at it as it’s apart and not the pricey .
If a good truck I would fix as anything under 10k in repairs is way cheaper then replacing .
Can’t sell or at least I couldn’t knowing it has a big repair bill required .
IMO
 

AreWeThereYet

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$7600 I believe is a pretty fair price as it’s a lot of work .
Upgrade the head bolts and anything else that will improve longevity while your at it as it’s apart and not the pricey .
If a good truck I would fix as anything under 10k in repairs is way cheaper then replacing .
Can’t sell or at least I couldn’t knowing it has a big repair bill required .
IMO

But you still don't go head first without getting other quotes
 

tko sled ed

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My 11 now my sons is going in Monday for head gaskets this will be the fourth time since my 04 seems like regular maintenance at about the 250 mark for gm. One was WARENTY one I paid for and one I paid for labor no parts but that 7500 mark is where it’s at good thing with the dealer is 1 yr warranty unlimited Kms
 

tex78

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Being a diesel tech at a g. M dealer


My suggestion is, if you do, do it

Don't cheap out, put new injectors in, put a new cp4 injection pump, question the turbo also

Injectors and turbo for the most part will be included in the labor and be just parts

Cp4 pump be a little bit of extra time, but if the pump goes, and takes the hole high side fuel system out, it's going to be a bigger bill than that

Kind of a bite the bullet thing, I always quote a client this way, cause I know the labor is a killer, and to do it twice makes absolutely no sense
 

tex78

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My 11 now my sons is going in Monday for head gaskets this will be the fourth time since my 04 seems like regular maintenance at about the 250 mark for gm. One was WARENTY one I paid for and one I paid for labor no parts but that 7500 mark is where it’s at good thing with the dealer is 1 yr warranty unlimited Kms
Bad luck, I've seen a few

More and more 11-16 lml out there having issues

06-10 lbz and lmm are non existence unless cranked up
 

Merc63

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Tex, is it because guys are tuning them up?? How does a head gasket let go all of a sudden?
 

sirkdev

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Heat cycles but bad tuning doesn’t help. On a good tune with the same cylinder pressures there should be no difference.
 

tex78

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Tex, is it because guys are tuning them up?? How does a head gasket let go all of a sudden?
I've seen and heard stock ones have issues

Alot I really think is pulling hard and running hot, the rad gets plugged up between the intercooler and rad, with fuzz and crap

No one uses screen in the front any more it seems

First thing I did with my lmm, wash rad out, cleaned and screened the front in, and it was at least 1/3 plugged up
 
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JMCX

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I put 425k on an 11 without issue. My coworker had a head gasket go on his 14 at around 200k. Dealer charged $5k for that and it was hard to swallow. $7K seems absurd. Bayman on here had his done under warranty. Dropped it off in the morning and got it back that night. The guys who know this job are making a lot of bank.
 

deaner

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It seems like an insane amount of money. How much in parts? How many hours does the book say? How many does it actually take a decent mechanic?
 

brad6

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I''ll have a better idea tomorrow. I knew it wouldn't be cheap to fix. Was talking to a guy last week at work, said his 12 duramax work truck was $11g repair and then ended up putting #7 piston through a few months later.
 

pfi572

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I''ll have a better idea tomorrow. I knew it wouldn't be cheap to fix. Was talking to a guy last week at work, said his 12 duramax work truck was $11g repair and then ended up putting #7 piston through a few months later.

Have heard that long block reman’s are around the $12-13k mark .
I haven’t checked myself but maybe Tex or someone else will weigh in .
Might be another option as well ?
 

tex78

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I put 425k on an 11 without issue. My coworker had a head gasket go on his 14 at around 200k. Dealer charged $5k for that and it was hard to swallow. $7K seems absurd. Bayman on here had his done under warranty. Dropped it off in the morning and got it back that night. The guys who know this job are making a lot of bank.
No friggin way it was done right

Cab lifted up even

Heads where not sent out and checked
 

tex78

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I''ll have a better idea tomorrow. I knew it wouldn't be cheap to fix. Was talking to a guy last week at work, said his 12 duramax work truck was $11g repair and then ended up putting #7 piston through a few months later.
And that's the next thing

Seal up the top end, now it burns oil or has catastrophic issue



Also why I quote out long blocks as a viable option too
 

tex78

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Have heard that long block reman’s are around the $12-13k mark .
I haven’t checked myself but maybe Tex or someone else will weigh in .
Might be another option as well ?
Last one if I recall, was 10 ish


About the same labor to re and re a long block to a head gasket job too


Especially if heads are bad shape, the parts add up, lots of gaskets used for either job
 
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