LLY: Possible reasons for updated/studded HG failure?

[thunder550]

Seems as though my head gaskets have failed again. I did them about 10k miles ago, used the updated OEM gaskets and studs. I read in another one of my threads that there may be a correlation between water pump replacement and HG failure? I just did my water pump about 2 months ago. Installed a new Bosch unit. When I did my HG's I did not have them machined. I checked flatness with a straight edge and feeler gauges and didn't see a problem. Ideas?

 

[PACougar]

Did you have the heads checked/resurfaced when you did the hg job?

 

[thunder550]

Nope. I checked them with a straightedge and a feeler gauge. They looked ok to me so I cleaned them up and reinstalled.

 

[PACougar]

Other than just plain bad luck, which is my specialty, I think all you'll have are complete guesses until you take it apart.

 

[andy-stevenson]

You going to have the heads done this time just to be sure?

 

[TheBac]

Just how would running a new water pump make headgaskets go bad? That doesnt make any sense.

 

[02greysixer]

Just how would running a new water pump make headgaskets go bad? That doesnt make any sense.

I think it's coincidence more than anything. A water pump starts leaking, people assume from general wear but in some cases from the added pressure on the cooling system from head gasket failure. They replace the pump, pressure now has nowhere to bleed off and it moves to the next weakest link.

I did the pump on my lly 30k+ miles ago and my head gaskets are fine. I have also done pumps on other trucks without head gasket failure

 

[onebaddmaxxx]

I have done many head jobs at the dealer, and they never pay to have the heads checked. Never had any issues. But also on stock trucks.

 

[thunder550]

You going to have the heads done this time just to be sure?

Yes, I'll definitely have them done this time.

I think it's coincidence more than anything. A water pump starts leaking, people assume from general wear but in some cases from the added pressure on the cooling system from head gasket failure. They replace the pump, pressure now has nowhere to bleed off and it moves to the next weakest link.

This kinda make sense I guess...

I have done many head jobs at the dealer, and they never pay to have the heads checked. Never had any issues. But also on stock trucks.

Yeah I couldn't understand what could happen to make heads warp, but who knows. I am far from an expert in those kinds of things.

 

[onebaddmaxxx]

6.0 heads YES they have to be checked as they will warp. They actually blow at the fire rings on the gaskets. The blue material is usually gone. Iv also done many of them, and some of them are pretty far out. the alum will flex pretty easy when torqued on on the duramax though.. Cleanliness is most important.

Almost all of the heads iv pulled off, had headgaskets that looked like this, which indicates a manufacture failure. Not necesarily from high boost or heat. just simple bad batch. Probably why gm switched from crimped gaskets to riveted

 

[thunder550]

These are the updated riveted gaskets though, with studs...that's what I am confused about. Going to be a few weeks before I have a chance to start tearing into it, but I'll definitely post pics of what I find.

I think I'm going to try and lift the cab this time, hopefully will make things easier.

 

[onebaddmaxxx]

yeah, iv only lifted chevy cabs on lmls. Def makes it easier to work on them. Had a few issues on them with heads, and oil pumps as well.

 

[Cheapskate207]

I wasn't going to bring my heads to the machine shop but at the last second decided to... they ended up taking .008 off. I had never overheated the truck, headgaskets let go and I didn't drive anymore. I know you said you checked the heads but is it possible they were still a warped a little? Other causes could be the gasket was damaged when you were setting the head on or head/block wasn't cleaned completely. Regardless they let go again, and that sucks man cause it's a total suckjob.

 

[thunder550]

Decided to pull it. Oil pan has been seeping for awhile, so I'll fix that while the motor is out.

 

[TheBac]

Man, your wife must be sitting there just shaking her head, wondering WTF you're doing. :roflmao:

 

[thunder550]

Man, your wife must be sitting there just shaking her head, wondering WTF you're doing. :roflmao:

That makes two of us!!

 

[TheBac]

Dont worry. My wife has for a long while. I think its normal for them. :roflmao:

 

[SilveradoTwins02]

6.0 heads YES they have to be checked as they will warp. They actually blow at the fire rings on the gaskets. The blue material is usually gone. Iv also done many of them, and some of them are pretty far out. the alum will flex pretty easy when torqued on on the duramax though.. Cleanliness is most important.

Almost all of the heads iv pulled off, had headgaskets that looked like this, which indicates a manufacture failure. Not necesarily from high boost or heat. just simple bad batch. Probably why gm switched from crimped gaskets to riveted

Yes. That looks familiar!! Both sides on my motor blew at that exact spot too!
Passenger rear and drivers front corner

 

[thunder550]

Drained the oil, everything looks good there.

 

[thunder550]

Got the heads off today. I don't see any obvious failure points on the gaskets.