Morning Subaru fans 🙂 

ive been lurking around for a while looking at various posts and learning about the WRX’s and what to look for when buying, and only signed up the other day. 

I wanted to ask owners something I spotted on a 03 wagon with 100k miles. The intake manifold had what can only describe as black oily soot on the drivers side near the Y pipe. Passenger side was clean and no deposits. 

Is this something typical of a higher mileage car that’s not had the engine steam cleaned and nothing to worry about. Or could it have been caused by a leaking pipe/gasket anywhere causing the fouling?

 

thanks in advance 

Hi n welcome to s.o.c, looks like that has got a prodrive y pipe , is it a ppp wrx wagon ?

Can't say it's always usual to see oily deposits in that area no matter what the mileage is . Most likely and cheapest reason would be 1 of the 3 oil breather pipes in that area .as these do get brittle due to the heat cycles the turbo creates and can crack . 

It's quite close to the turbo so oil lines or turbo seals could be a possibility but if the seals were gone id expect blue smoke on boost or coldstart .

Either blocked pcv valve or exessive oil breathing could also lead to oil leaking there .pcv is cheap enough to clean or replace  but excessive oil breathing caused by the engine could be something more sinister like piston blowby  (Although most unlikely).

Make sure you have a look for splits on the 1/2" bore black breather pipes that run from cam cover to inlet and crankcase .

Hear it start from stone cold to check for piston slap noises  and while its running remove the oil filler cap , if its breathing heavy it will "chuff" a lot as you remove the cap (a little is normal)

 

Best of luck 

Thanks Savage Bulldogs

really appreciate the response. Lots of info in there. Yes it’s a PPP - checked with IM group following seeing a post here, and they confirmed it’s a legit PPP.

ive not yet gone to look just noticed the deposits last night while debating whether or not to make the trip. It has full service history with stacks of paperwork so I beleive. 

If I look I’ll have to check everything you mentioned plus the paperwork to see if any breather pipes have been replaced.  

 

Thanks a lot for the help!! 

Welcome!

Adding to Savages comments and not related to the oil but check you don’t get any rattling at middle rpm either.  Always a must check. 

Wotcha and welcome!