[Aero Bob]

Over the last couple of months i've noticed an amount of oil leaking from the oil filler cap on my 1993 Aero.

Every time I go to check the dip stick an amount of oil poors from the top of the filler cap. I have also noticed a patch of oil soaked into the sound proofing to the rear of the filler cap.

Although i'm no professional this says to me that the oil is being pushed from the top of the filler cap under pressure.

Do any of you good folk have an idea what may be causing this?

 

[billj]

Welcome to Saabscene, Rob.

It sounds like the non-return valve in the crankcase ventilation hose has failed, allowing boost pressure to pressurise the crankcase. It's the round, white plastic piece in the hose that runs from the Y-piece on the cam cover to the inlet manifold.

You'll want to sort it out as it will be putting the oil seals under strain too, which could lead to more expensive work if they fail.