lifting the heads under boost? air + oil in coolant

gxnos

Founding Member
Apr 14, 2002
173
1
0
Birmingham, MI
basically stock 5.0 with an on3 kit MPT70 turbo, 9psi, a little over 500hp..

A while ago I noticed my overflow bottle was brown. Found out its oil... sweet. Another time, I noticed the overflow was bubbling, almost like a boil. This means a bunch of air is being released by the cap, so air (or exhaust) in the cooling system... sweet.

After a few times of flushing the system and filling it up with water, it seems intermittent. It seems like only oil / air is getting into the cooling system after beating on it. If I drive normal, its fine. Compression is fine, leakdown is fine, oil is fine. Actually, it always seems fine, coolant temps are fine and it runs awesome.

Think I might be lifting the heads? I might try swapping out the head bolts for ARP, if it doesnt work, I'm pulling the heads. You guys think I might get lucky?
 
Well, if leak down and compression checks come out good, then I really don't see how a failed head gasket would be culprit.

That, and I have a buddy that was loosing coolant the same way in his stock motor Honda. He did studs and solved the problem.
 
basically stock 5.0 with an on3 kit MPT70 turbo, 9psi, a little over 500hp..
Think I might be lifting the heads? I might try swapping out the head bolts for ARP, if it doesnt work, I'm pulling the heads. You guys think I might get lucky?

This is exactly what started happening to my highly boosted car under extreme flat out cooler air higher gear runs only. Even tho' had installed special metal head gasket and ARP bolts. Make sure you find out from ARP the "proper torque" and sequence for their studs. I do remember they said to run a tap thru the threads first and install studs only "finger tight" then the torque on the nuts was really high compared to stock or stretch bolts. Also make sure there is no interference with the valve covers with higher studs or you'll have a major oil leak requiring some reshaping of the valve cover.

If you do all this and it still happens you will either have to reduce the max boost or o-ring the heads for a better seal.
 
I think your cure may be only temporary.
At some point you are going to have to replace the head gaskets. Once that path for water opens up, it's never the same again.
 
at this point it has lasted longer than when i originally put it together, so i say its a success. HG may be on borrowed time, but i dont think so anymore. its possible that no damage was done during the stretching of the bolts. ill keep you guys updated :)
 
at this point it has lasted longer than when i originally put it together, so i say its a success. HG may be on borrowed time, but i dont think so anymore. its possible that no damage was done during the stretching of the bolts. ill keep you guys updated :)

Could be. Hopefully not! Glad to hear it is fixed!:nice:

PMed you.