LB7: Head Gaskets? Please Help

J

jcriddle

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Dec 28, 2012
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I replaced my head gaskets 8 months ago or 15,000 miles on my 2003 LB7 and I am now having similar symptoms. Heater blows cold when Idling, coolant system stays Pressurized.

I replaced all gaskets and Head Bolts, Water Pump, coolant.

It is programmed at 90 hp above stock and I do run EGT's up to 1600 degrees.
Stock Exhaust, Stock air Intake. ????

What am I missing for this to have happened again?

If I do them again what would you recommend?
 
IOWA LLY

IOWA LLY

Yes, its really me
Feb 23, 2007
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What did do regarding the injector cups? Did you have the heads checked out by a machine shop?

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J

jcriddle

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Dec 28, 2012
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I did have the head checked out and all the cups reseated. It was a concern and I didnt really want to do this again.
 
J

jcriddle

New member
Dec 28, 2012
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Is the Block Deck Torched? Not sure what you mean..

It was never overheated to the red and has never been over 210 since the heads where done last.
 
J

jkholder09

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Jan 8, 2012
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When a compression ring pushes out on a head gasket continued use will mar the head.
It looks simalar to a blow torch on steel.
If the block surface is torched it will be difficult to seal a head gasket.


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J

jcriddle

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Dec 28, 2012
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When I did the heads the first time I used gm head gaskets any suggestions? I also used stock head bolts and not ARP thoughts? I run about 25psi boost will this cause premature HG problems?

When I replace them again what do you suggest for gaskets, gasket adhesive, brand, ARP bolt, cup sealant, ???

The heads where milled last time but the gasket embedding lines where still visible? Is this a problem?
 
dmaxbowtie

dmaxbowtie

Duramax fiend
Jun 2, 2011
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Possibly a cracked injector cup? I would highly doubt a head gasket leaking by again if the heads and block deck were In good shape.
 
J

jcriddle

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Dec 28, 2012
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Yes I currently have pressure in system with very little coolant lose

1/4 gal in two weeks max

Oil is not milky
 
S

S Phinney

Active member
Aug 15, 2008
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Pressurize the system using a tester and give it 15 minutes and see if you have a cylinder hydro locked. That would give you a starting point to look.

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IOWA LLY

IOWA LLY

Yes, its really me
Feb 23, 2007
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jcriddle said:
When I did the heads the first time I used gm head gaskets any suggestions? I also used stock head bolts and not ARP thoughts? I run about 25psi boost will this cause premature HG problems?

When I replace them again what do you suggest for gaskets, gasket adhesive, brand, ARP bolt, cup sealant, ???

The heads where milled last time but the gasket embedding lines where still visible? Is this a problem?
Click to expand...



If there were still grooves in the cylinder head after they were milled then you shouldn't have reused them. Sounds like you may have a head gasket leaking again.



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