Headgaskets? heads lifting?

[John]

When I drive on higher boost levels (around 15lbs) my coolant overflows into the resivoir. I've bled it countless times, so I know there is no air somewhere in the system.

I suspect its either a head gasket or the heads lifting off the deck under high boost. I can't seem to get any kind of straight answers from anyone as to what route to follow on resolving this.

Ive done a compression test and it checked out ok...

any ideas?

 

[IGOTASTi]

Have you done a pressure test on the coolant system, or a dye test?

 

[John]

coolant pressure test checks out OK...i haven't done a dye test though. There are no leaks anywhere or anything like that.

I'm not even entirely sure about head or gasket failure because i never have to add coolant...just dump it from the resivoir back into the cooling system...I never actually lose any

 

[HolyCrapItsFast]

This happened to me twice now and each time it was the head gaskets.

The only way I have found to prevent this from happening is to ensure that both the surface of the block and the head is perfectly straight and smooth and use new bolts or studs. Stock gaskets seem to be the best ones to use IMO.

 

[John]

My engine has never been disassembled, so if its a mating surface problem, its from the factory...but with that being said, my 20R was from back in 97...so it has some years on it....but its still fairly low mileage for its age (about 75k on engine).

Does anyone know where I can source 20R gaskets? OEM thickness is 1.6 but I can't seem to find them anywhere.

 

[Bluedemon_II]

Japan.

I doubt that your heads are lifting at your power level "considering that the internals are stock". I would suggest to get the dye test to see if there are hydrocarbons in your coolant. If it test positive then its a head gasket problem. Did the engine overheat in the past?

A source for the Head gasket would be: http://www.tonyrigoliperformance.com.au/products-subaru_engineparts.html

They are an Australian company, I doubt that you will find that Head Gasket in Atlanta. Its not a common engine.

 

[John]

I sent them an e-mail. Thanks for the referral.

I'll do a dye test as soon as I'm able to. I've never overheated the engine. I came close to it once, but I shut it off before it passed 200F and let it cool

 

[Scott Stokes]

I just started up a 03 Wrx today that I rebuilt the motor on for this same problem. It 90% sure its probably head gasket. And I will bet u a dollar its only on the right cylinder head.

 

[John]

there is no air in my coolant system. I've bled hundreds of coolant systems before, so I know that this is not the case.

There is minor smoke out of the tail pipe at startup, but thats from running rich (stand alone ecu settings I cant get right)...but after it warms up its ok.

I'll do HGs when I have the funds. I'll do water pump, timing, head studs, etc with it as well.

Should I send the heads to the machine shop, or do you think I'll be ok just slapping gaskets on? How can I accurately tell if the deck and the head are true?

 

[Scott Stokes]

there is no air in my coolant system. I've bled hundreds of coolant systems before, so I know that this is not the case.

There is minor smoke out of the tail pipe at startup, but thats from running rich (stand alone ecu settings I cant get right)...but after it warms up its ok.

I'll do HGs when I have the funds. I'll do water pump, timing, head studs, etc with it as well.

Should I send the heads to the machine shop, or do you think I'll be ok just slapping gaskets on? How can I accurately tell if the deck and the head are true?

Have heads and block shaved. Save your self future issues. Replace valve guides while there too.