Messed up Valve... maybe?

[Andyjo]

It's been a long-long time since i've posted... the OBXT has 213k on it and i seem to have hit a wall...

About a year ago i was having an issue w/ some mis-fires on cyl#2, eventually found the problem was a vac. line had popped off the intake manifold. Popped the thing back on and the car ran awesome!... for a day.. until i stupidly ran seafoam through it (because 1/2 the vac lines were full of that white oily crap), had the RPM's high... but it stumbled a few times and coughed... and stalled out... ever since then the misfire came back... so i dealt with it for a while...

 

Fast-forward to this week, had to get the car inspected, it's missing ALOT now, enough to throw a CEL, and make it noticeably crappier to drive. So since i was over-due, and had a bunch of other things that i needed fixed and didn't have time to do myself, i brought it over to the dealership... They found the same thing i did, 20% on cyl #2 on a leakdown test...

 

Of course they offer to tear it apart @ the nice cost of $2-2500... on a car that's worth maybe $2000... anyhow, tell them no thanks, we bought a new outback, and my OBXT is back in the driveway.

 

So... It's either a valve or a messed up piston/ring. I'm guessing more valve than the piston, mainly because when i rebuilt it @ 168k it ended up w/ forged pistons... not completely ruled out, but i'm guessing not. Where do i go from here? Stuff some air into the cylinder and find where it's coming out? If it is a valve, i guess that means i need to tear the motor out again, pull the head and then play with that? When i did the motor before, i had the heads done for me... is it really that hard?

 

Anyhow, good to be back!

[Ianauto]

Luckily it's Cyl 2 which is the "easy" (no pun intended!) head to remove.

You need to perform a Leak down test, very well may have burnt an exhaust valve since you used forged pistons. Usually with a problem like your describing I just pull the head, your gonna be either doing a valve or if it is a piston problem and you get lucky with no cylinder damage...Cyl 2 can be changed in the car if your crafty (I've done 5-6...takes patience). good luck either way

[Andyjo]

You’re right, out of all of them I’m glad it’s #2! When I ran a leakdown on it prior to the dealers diagnosis it was only holding 20%. I suppose if I’m going to have to yank the motor/head anyhow, I can drop the headers and blow some air in there to see if the exhaust port is where it’s coming from.

I suppose there’s no point in trying to check clearances before if it is in fact leaking through the exhaust valve.

I’m also guessing it’s not possible to pull the head w/ the engine in the car? All the work I did before I just tore the whole thing out and went from there.

 

 

 

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[Wills03rexwagon]

You’re right, out of all of them I’m glad it’s #2! When I ran a leakdown on it prior to the dealers diagnosis it was only holding 20%. I suppose if I’m going to have to yank the motor/head anyhow, I can drop the headers and blow some air in there to see if the exhaust port is where it’s coming from.

I suppose there’s no point in trying to check clearances before if it is in fact leaking through the exhaust valve.

I’m also guessing it’s not possible to pull the head w/ the engine in the car? All the work I did before I just tore the whole thing out and went from there.

 

 

 

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Twin cam engines have to be pulled out in order to remove the heads.

 

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[Andyjo]

Yeah.. i remember how much of a PITA it was with the engine out.. i can only imagine how much of a hassle it would be with it in. Wasn't sure if there was some trick.

[Ianauto]

The Driver side head can be removed in the car no problem, i do them all the time. Remove the basics: Rad/Fans/Intercooler/Battery/Airbox (room to move engine over...). Remove your belts & timing plastics...now the fun part, remove your cam sprocket bolts on the driver side before removing the Timing Belt (my favorite way is Irwin 53915, you need to hammer it over the bolt head then a 1" socket w/ breaker bar)

Once there off...disconnect the driver side exh manifold and the cross manifold(straight pipe connecting to pass side header)

Disconnect both the 14mm nuts holding the bottom motor mounts to the frame.

Back up top, disconnect the "dogbone" mount under the intercooler.

Remove the plastic Coolant tank driver side of intake...

Loosen (don't remove) the (4) 12mm (not the 10mm...) bolts on the driver side intake manifold

Remove the same 12mm bolts on the passenger side

Now here's where you need to be a bit creative:

I usually use a prybay and gently lift the Driver intake up about an inch off the head (that's all you need)

Now...block of wood under oil pan, GENTLY jack up until the bottom motor mount bolts are out of the frame/cradle

Ratchet Strap: I usually go Alt/AC bracket & over the the inner fender (various holes). Ratchet the engine over...you can get it just about touching the passenger side (helps if you have a helper to "shake" the engine a bit as your ratcheting).

You know have the room, I do this in my shop weekly takes me 2 hours to have the Driver head in my hands (albeit easier on a lift)

You will wind up with the (3) bottom head bolts not having enough clearance to remove from the head while removing, thats ok you just need to work with the room you have and remember to put the head back in with those 3 bolts already in the head. It's very doable, just go slow.

Also if you've never removed a head on one of these, mark your cam buckets...they need to go back to there corresponding valve. Good Luck!!

[Ianauto]

...Forgot to mention, you will be dropping head out the bottom!

[Andyjo]

Great info Ianauto! Sure beats tearing the whole engine out!