Head Gasket failure what to check before teardown?

[brentstrecker]

I'm about to tear into a 97 Outback with a EJ25 and automatic transmission. It's burping out radiator fluid sporadically.

 

It's has a 96 engine in it with the DOHC and hydraulic valves. Should I get the 97 - 99 heads? From what I understand they increase power 10hp and don't recommend High octane gas.

 

Also the Trany has 260K miles on it and shifts hard from 1 to 2nd. The other gear shifts are smooth. The oil in it appears to clean and new looking. Does it need rebuilding?

 

I was thinking of doing a compression check. Any other things I should look at post op?

[Caboobaroo]

I would personally go for the shim over bucket EJ25D heads myself but that's because I have more experience with those.

 

Most higher mileage 4EATs have a harder shift from first to second. I've even done a rebuilt transmission in one and the first - second shift is almost as hard. If it's not slipping then it should be fine.

 

Just make sure the head surface is flat on whatever heads you use.

[GeneralDisorder]

You can't use the later (46cc - down from 55cc) heads without also changing the pistons or you will increase the compression to around 11.5:1 and will definitely require premium fuel. It will increase the power but if you are going to go that route you might as well just use the EJ22 heads (40cc) and get it up to 12:1 for max performance. It will pull the torque up a lot higher. The HP is around 190 but is generally considered to be limited by how much the 2.2 heads will flow up high.

 

GD

Edited November 24, 2011 by GeneralDisorder

[brentstrecker]

Thanks for the advice guys. I was wondering how the compression would change with the newer heads. I'm more after good gas millage and regular gas than increasing performance. The motor only has around 60K miles on it so the bottom end should be good. But I don't know how long the head gasket has been blown or if the engine has over heated causing damage. It's fairly quiet running and the oil looks good and has been changed every 3K miles. Is it best to just of make sure the original HLA heads look good and but new gaskets in? What about finding a newer model engine? Also the engine seems to have power but accelerates very poorly at times. It falls on it's face if pressing on the throttle to hard.

 

Is there a list of the different cylinder head specifications somewhere?

 

Thanks again!