I think that several people have tried to make this clear. The oil warms up
and water evaporates out into the crankcase. the PCV valve allows the water
vapors to be sucked from the crankcase into the intake manifold. It is mixed
with the intake air goes through the cylinder and pumped out the exhaust. It
is not a closed system since the vapors are free to exit the motor via the
exhaust ( while running ).

"Dave Stadt" wrote in message
news

"mikem" wrote in message
ups.com...
Crankcase fumes are sucked into the induction manifold (and burned by
passing through the engine) via the Postive CrankCase Ventilation check
valve.

The question still remains....how does the moisture escape as modern
engines are not vented to the atmosphere but are a closed loop. We aren't
talking about crankcase fumes but about moisture supposedly being boiled
off into the atmosphere.