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New guy, blown head gaskets

ak diesel driver said:
Precup in #4 looks like a big crack in the picture.
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yeah its cracked, but its not even the worst. they all are. id say #8 is the worst
Will L. said:
Do some good clean up for better inspection. You might get away cheap with it, hopefully.

Were you able to get compression numbers? That would prove your washed gasket theory (which looks right to me), and tell you if you should get into the lower and right now or not.

Have you cleaned and inspected cylinder walls yet?
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i did, they look fine. i dont have the stuff to do compression... yet. found an old kent moore tool kit for 6.5s. i should be able to all kinds of testing with it. whenever it gets here
n8in8or said:
I think the brown in #4 is because that is the cylinder that is tied to the EGR system.
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my fault, shouldve mentioned this is a f code. '98 C3500. im guessing a bad injector. theyre all getting rebuilt with bosch nozzles.
 
got some questions while i wait for parts stores and the machine shop to open on tuesday

were their any years of oil cooler lines that were NOT problematic? or are they all junk?
recommended head bolts? dont really have the funds for ARP yet
what to use to seal head bolts and intake bolts with?
what to use to seal valve covers with?
can any style of turbo work? (2,4,3 or 5) the old one has probably 3/16-1/4 of play in the shaft (its brutal) GM8's are hard to come by. tons of cheap horizontal wastegates for sale locally though
 
All oil cooler lines were problematic. That's why there's aftermarket kits.
Never have heard of one brand being better but they do come with thread sealant on them.
Use "the right stuff" to seal the valve cover. Put a bead on and get it making contact everywhere and then let it cure and finish tightening after that.
The only real difference in the turbos was the way the wastegate was positioned. As long as you can deal with that your good to go.
 
ak diesel driver said:
All oil cooler lines were problematic. That's why there's aftermarket kits.
Never have heard of one brand being better but they do come with thread sealant on them.
Use "the right stuff" to seal the valve cover. Put a bead on and get it making contact everywhere and then let it cure and finish tightening after that.
The only real difference in the turbos was the way the wastegate was positioned. As long as you can deal with that your good to go.
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The lines on my '98 look better than the ones on my '96. You know, not the ridiculous push-in clip kind. Thought maybe they were better. Guess I'll be replacing them too
 
Newguy1998 said:
my fault, shouldve mentioned this is a f code. '98 C3500. im guessing a bad injector. theyre all getting rebuilt with bosch nozzles.
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Even if the truck doesn't have EGR, the passage is still in the head and I think it still affects things a little......maybe not, but take a look and see if that is the cylinder that it ties into the intake port - if so, then that may be a clue. Still, check your injectors, yes, but if they are ok at least you won't be left totally scratching your head.
 
ak diesel driver said:
All oil cooler lines were problematic. That's why there's aftermarket kits.
Never have heard of one brand being better but they do come with thread sealant on them.
Use "the right stuff" to seal the valve cover. Put a bead on and get it making contact everywhere and then let it cure and finish tightening after that.
The only real difference in the turbos was the way the wastegate was positioned. As long as you can deal with that your good to go.
Click to expand...

Do you guys know if the oil coolers were different from year to year? I know the ports are 1/2" in the #506's & 3/8" in the #141's. I'm just wondering if the oil cooler hoses I have from my old '96 (leroydiesel.com) will work in this '98. With different block fittings of course.
 
GM has spec on how long the cracks can be on precups and still be serviceable. Your budget... I run cracked stuff and win carnage threads. Precups are the least of my concerns. I won't run a cracked head, but, will run a cracked block...

IMO the light brown is like a spark plug tip - got hot from lack of coolant flow on that head due to popped gasket. Carefully check that head for cracks.

Shameless plug for site vendor @Burning oil who makes an aftermarket oil cooler hose kit. GM's hoses can't handle the temperatures and the hose gets hard then leaks or comes apart at the crimp. Leroy Diesel's stuff held up when I was ruining engine oil, due to temps, on one of the hot rods I built. Don't forget to clean out behind the oil cooler.
 
WarWagon said:
GM has spec on how long the cracks can be on precups and still be serviceable. Your budget... I run cracked stuff and win carnage threads. Precups are the least of my concerns. I won't run a cracked head, but, will run a cracked block...

IMO the light brown is like a spark plug tip - got hot from lack of coolant flow on that head due to popped gasket. Carefully check that head for cracks.

Shameless plug for site vendor @Burning oil who makes an aftermarket oil cooler hose kit. GM's hoses can't handle the temperatures and the hose gets hard then leaks or comes apart at the crimp. Leroy Diesel's stuff held up when I was ruining engine oil, due to temps, on one of the hot rods I built. Don't forget to clean out behind the oil cooler.
Click to expand...

I believe I read 3/16" for the length of cracks on the precups. Which I'm sure these exceed that.
 
EWC said:
I'd be worried about those cracks between the valves .
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I'd be more than worried. That head is trashed. Valve seat cracks invariably penetrate into the coolant passage and leak. That's as sure a bet as the Pats beating the Falcons in Super Bowl LI (which I did, bet on the Pats). If it isn't leaking now, it will the first time it undergoes any thermal stress.
 
WarWagon said:
@Newguy1998 they are referring to this head crack.

View attachment 49902
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Thanks, @WarWagon , don't have the ability to insert circle thingies into photos on my phone! When the head is cleaned up, I wonder if there are other cracks between the seats. Then there's the whole other issue of the other head's condition. To lose that much coolant really thermally stresses those heads.
 
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