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RE: Crank Seal

> I would like to know how the seal whistles if it doesn't leak oil, one
> would assume that if air can pass then so can oil. Does it leak
> oil?????

Positive crankcase pressure (blowby) < negative breather pressure.

More common on turbo engines than n/a ones, but not unknown.  In part a
symptom of good piston rings.

And no - the fact that air can pass doesn't mean that oil could pass.
The internal rim of the seal is a micro-pump.  Cut one in half sometime
and look at it under a microscope - the profile is quite complex.  This
is why the seal should be oiled (but NEVER greased) during assembly.

 Phil Payne
 UK Audi quattro Owners Club
 Phone +44 7785 302803  Fax +44 870 0883933