Sooooo my headgaskets are bad. Now what?

[Benfolio]

Okay, phase I EJ25, 162,000 miles, no clue of service history.

TWICE now my coolant bottle has over flowed leaving alot of air in the radiator and not much else. Caught it both times before the engine got too hot.
First time it happened was when I had first gotten the car last summer, and I figured it was just overfull. Never did it again.
This past winter I noticed the heat would go cold when stopped, and only raising the RPMs would bring it back. Replaced the t-stat. Same issue came back. Once or twice I noted the temp gauge climbing, found out the cooling fans weren't turning on unless the A/C was on. Replaced the coolant temp switch, all is good now.
BUT.
Still going cold when stopped. SOMETIMES.
And then.....
Coolant overflowed out of the tank when I was driving it hard after my WRX strut install a couple weeks ago. Had to test em out on curvy pavement... and mud.
Had to stop, in the rain, take the overflow bottle off, and pour it back into the radiator. FUN.
Ever since then, the bottle hasn't overflowed, and I have tried burping the system till I was blue in the face, thinking it was just an air pocket from when I did the t-stat. No luck. Still getting air in there. Because occasionally it still goes cold, and I can hear the coolant gurgling in the heater core in the morning.
Now I've taken this car on long trips before, and I drive 15 miles each way to work everyday, but after my beat-run I'm scared to go far with it now.

So yeah, it's probably head gaskets. Compression gasses are getting into the coolant. No leaks externally.

But will it be okay, and for how long? Will it blow up this summer?

I want to find a motor to rebuild before it does, cheap, and have it ready to go in when my 2.5 does croak. Or before, depends.
Otherwise I could always opt for a low mile JDM engine (more plentiful and cheaper than a used or reman USDM motor).

Is this the way to go? Or should I suck it up, pull MY motor, and throw headgaskets on it? I can get parts cheap enough, and do the work myself. Shouldn't need to send the heads out to get checked.... right?

Opinions in 3...2....1.... :smt022

[Huffer]

That doesn't sound like a typical HG leak to me. Normally you lose coolant and the overflow bottle gets oily. Sounds to me like you have a blockage in the rad.

You can actually drive a leaking HG for several thousand miles - just don't put any real load (3500rpm + loaded vehicle + hill etc) on the engine and it'll be fine. Eventually if a HG goes bad it will need to be replaced.

At anyrate, you're better off just replacing the HG's - if you can do the job yourself you'll save a lot of money, just make sure to get the heads milled for a flat mating surface.

Even better, while the heads are out, see if you can send the cams off to get a street grind from Delta.

[Piddster]

Take a sample of the coolant to get tested, and you'll know right away.



If you opt to change out the headgaskets, do not use the specified replacements. Use the STi or Felpro gaskets. Three years ago two of my friends at one of the dealers here started using STi gaskets, and cars never came back after that.

[Benfolio]

Well the overflow IS filthy..... I cleaned it out once but it still looks icky in there.

I just remembered, we do have a kit at work for checking HG's, it tests for combustion gasses in coolant. Maybe I'll give that a whirl.