DIY: Head Gasket Replacement

[slbert]

Just did my HG this weekend, with motor in the car. I did it without undoing the motor mounts, and the only challenging parts were: 1. being able to do a phenomenal cleaning of the pistons, but where the gaskets sit was easy to access (I took off the intake manifold)
2. The head bolt torquing sequence is a challenge for backing off and re-tightening the bolts to the specific angles (-180-180+90+90) because you can't swing a wrench the full number of required degrees....If you mark the head bolt with something that can't rub off it will help.
Other then that, it was fun, seeing as I had never done anything like it before.

[daprezzjp]

great post!!!

[BrysImpreza]

Thank you for this write up, as I am nearing 110K on a SOHC 2.5, I have the feeling I may need to be doing this soon.

[notmoving]

I'm searching and searching for a DIY for the 2.0 DOHC turbo - an 02 wrx. I can't tell for sure if we have to take the engine out or can do it in the car, but in the manual it says to remove the camshafts... This seems like overkill somehow.

Anyone have any advice or a write-up on the 2.0 DOHC?

[luckysubie]

Don't quote me on this, but I'm pretty sure the cams have to be removed on DOHC applications. Reason being the cams cover the head studs.

[ALL NATURAL]

Originally Posted by notmoving

I'm searching and searching for a DIY for the 2.0 DOHC turbo - an 02 wrx. I can't tell for sure if we have to take the engine out or can do it in the car, but in the manual it says to remove the camshafts... This seems like overkill somehow.

Anyone have any advice or a write-up on the 2.0 DOHC?

You must take the motor out and you must take the camshafts out. The head bolts are behind the camshafts; therefore, unreachable with the camshafts still in.

[elislider]

Originally Posted by luckysubie

Don't quote me on this, but I'm pretty sure the cams have to be removed on DOHC applications. Reason being the cams cover the head studs.

as poster above me has said, you must take the cams out to get to the head bolts

[beamerrs]

Ok im about halfway through doing this to my SOHC...

when i get to the point of taking off the heads do i need to rotate the motor for more room or should i be able to remove the heads without rotating the motor while its still in the car?

[slbert]

There is no need to rotate the motor, assuming you are doing it with motor in the car......BUT, it would be much easier to do the torquing sequence being able to access the head bolts with the motor rotated. I did it 2 months ago, motor in place, not rotating, and the head bolts are a pain. Plus, with the motor rotated, you'll be able to clean the pistons easier.
Just my $.02 worth.

[CatchMyDrift]

I had my uncle do my headgaskets for me in trade for some labor. He said he lost the paper with all the torque specs and bolt tightening rotations so he just used his own strength to tighten them all down 1 by 1. Since completion, the motor is still overheating on me.

Since he didn't use the:

1) Tighten all bolts to 29 N-m (3.0 kgf-m, 22 ft-lbs) in alphabetical sequence.
2) Then tighten all bolts to 69 N.m (7.0 kgf-m, 51 ft-lbs) in alphabetical sequence.
3) Back off all bolts by 180" first; back them off by 180" again.
4) Tighten the bolts (a) and (b) to 34 N-m (3.5kgf-m, 25 ft-lb).
5) Tighten the bolts (c), (d), (e) and (f) to 15 N.m (1.5 kgf-m, 11 ft-lb).
6) Tighten all bolts by 80 to 90" in alphabetical sequence.
CAUTION: Do not tighten the bolts more than 90".
7) Further tighten all bolts by 80 to 90" in alphabetical sequence.
CAUTION: Ensure the total "re-tightening angle" [in the former two steps], do not exceed 180".


could he have damaged the head gasket or left a leak somewhere? He put 5 quarts of oil in last night and now my dipstick is registering 6-7 quarts and the oil is thin.

wtf?