View Full Version : I have a 2002 Subaru Outback and I am getting a lot of oil in the air filter. What would be the cause? PCV?

01-17-2008, 12:53 PM
The hose coming from passenger side valve cover to the air box is oily.

01-17-2008, 04:39 PM
One of 2 things are causing this. 1. The worst thing could be motor blow-by. Smoky oil coming up from the bottom of the engine, mostly through bad piston rings. This probably requires a combination of high mileage and/or abuse. 2. A breathing passage way under one of your valve covers is clogged due to not changing your oil enough or improperly.

01-17-2008, 08:24 PM
sounds crazy but this happens on turbo trucks, maybe it can happen on yours? if your air filter is bad enough your motor still has to pull air in from somewhere, it'll try to pull it through that hose and it pulls out oil instead. sounds weird but it happens on turbo diesels all the time

01-18-2008, 12:10 AM
Take yur car for a long country drive. Go for a couple of days. When yu get home change the oil & add 1/2 tin of polymer( stp). You dont have to drive fast,just keep the motor running for long periods.

01-18-2008, 03:56 AM
Sounds like maintenance hasn't been done properly. Get a service done.

01-18-2008, 07:41 AM
A blocked PCV system can indeed cause this.. a pressure buildup in the crankcase will force oil into the air cleaner/ intake tube. If the engine has a lot of miles, or is driven hard, it could be blow-by caused by excessive engine wear. A simple compression test can confirm this. Given the reputation Subaru engines have for reliability, this isn't likely, but if the car was under-maintained or abused, it's possible. Even something as simple as overfilling the engine oil can cause it. 2.2 and 2.5L SOHC engines take 4.5 qts, 2.5L DOHC take 4.75, and all turbo models take 5.0 qts.

01-18-2008, 11:27 AM
it will have blocked breathers this is acommon fault on this model ..

11-05-2010, 04:28 AM
Pick up a "band wrench", if you can. They have a metal band that wraps around the filter attached to a handle ,As you turn it, the band will tighten around the filter.
You may Be Solve your problem.

11-19-2010, 10:24 AM
I agree with prince, you should try it!