Oil on top of engine

[Subie63]

I have an '05 LGT with 271k+ miles on the odo. and a bone stock engine. It has recently developed an oil leak from somewhere on top of the engine but under all of the intake clutter. I can see oil pooled in some of the valleys on top of the engine, and the excess is running down the back of both sides. I first noticed it maybe a month ago when I started smelling burning oil and noticed the pooled oil when I went in to investigate. There is nothing blatantly obvious that I can see as a source of the leaked oil, and nothing visibly spraying while the vehicle is idling. I'm wondering if this is something that only happens under harder exceleration while developing boost? Any help or suggestions where to direct my attention would be greatly appreciated!

[FJuan]

Which side is the oil mostly on? The P/S pump is known to leak over the passenger side of the motor. Check the P/S pump.

[relative4]

My money is on the breather hoses at the back of the block.

 

Suspect #1: 99071AC220, aka 1AC22 in this diagram:

https://parts.subaru.com/a/Subaru_2005_Legacy-GT-Limited-Sedan-25L-TURBO-5MT-4WD/_54102_6030705/WATER-PIPE-1-WATER-PIPE/B13-036-03.html

 

Suspect #2: PCV valve assembly (bottom section), 11815AB790, aka 11815 in this diagram:

https://parts.subaru.com/a/Subaru_2005_Legacy-GT-Limited-Sedan-25L-TURBO-5MT-4WD/_54102_6026547/INTAKE-MANIFOLD-INTAKEMANIFOLD-BODY--PCV-PIPE--06MY/B13-050-12.html

 

The pipe sections that run behind the IM in the second diagram, that include the end parts from the valve covers, the crosspipe, and the little section that feeds from the crosspipe to the turbo inlet can also leak, but most often you see the end pipes leaking down the valve covers.

[Subie63]

I've already replaced the plastic vacuum cross pipe that runs behind the IM, and the rubber lines that attach to it, so I can safely say that's not the issue.

 

As for the other two breather tubes you pointed out, I will give them a a good look-see tomorrow after work.

 

And to answer the question of what side of the engine most of the oil is laying, the answer is both. Although it does seem to be pretty damp around where the PS pump is mounted. I'll give that a shot too.

[apexi]

I'm not sure if things are the same on the turbos, but on my non-turbo there's also the oil pressure sensor under the alternator, wonder if the leak could be coming from there.

 

http://legacygt.com/forums/attachment.php?attachmentid=262194&d=1519179869

[robburns201]

Pcv maybe

[kzr750r1]

There is another crossover vent from the case to the heads as well as the one behind the intake manifold. Give me a moment and I'll take a picture. I have my intake off at the moment.

[kzr750r1]

You can see the vent for the PCV on the left and the large bent hose near the center line of the case is another. Your gonna need to pull some stuff off to get this fixed.