Re: couple 'o questions 2

[Andrei Kogan <abk@phy.duke.edu>]

> we
>took off the oil-filler cap and air was blowing out of the car.  is this
>supposed to happen, or is it supposed to suck in the air.  Thanks!!
>
>Richard
>'84 Audi 4000


The gas which blows out of a filler cap gets into the crankcase through the
imperfections in piston ring seals (blow-by) and follows oil lines  up into
the engine head. A little bit of blow-by is normal for the engine that old,
an excessive crankcase pressure may indicate a clogged crankcase vent (I
don't remember the details, I think there is a plastic "throttle"
connection at the back of the engine, on the engine