986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - 2004 Boxster non-s

Steve Tinker · 10-17-2011, 02:12 PM

A faulty AOS (air/oil separator) can cause both oil on top of the engine end also the build up of oil in the intake. Check the AOS for splits or an easier quick check is to try and remove the oil filler cap with the engine idling - if the cap is difficult to remove (ie vacuum) then there is a good chance the AOS is faulty.
If you are using the car on the track, Porsche make a "competition" AOS which is probably what you should use.

10-17-2011, 02:12 PM	#3
Steve Tinker Registered User Join Date: Dec 2008 Location: Queensland, Australia Posts: 1,522	A faulty AOS (air/oil separator) can cause both oil on top of the engine end also the build up of oil in the intake. Check the AOS for splits or an easier quick check is to try and remove the oil filler cap with the engine idling - if the cap is difficult to remove (ie vacuum) then there is a good chance the AOS is faulty. If you are using the car on the track, Porsche make a "competition" AOS which is probably what you should use. __________________ 2001 Boxster S (triple black). Sleeping easier with LN Engineering/Flat 6 IMS upgrade, low temp thermostat & underspeed pulley. 2001 MV Agusta F4.