oil separator does what?

[wdonovan]

Just what is the purpose of this part / system? The name implies to me that it separates water vapor from oil. I know where it is and what it looks like but I'm not familiar with a separator on any other type of engine and would like to understand it. So anyone.... what's it hook to? I can see at least 4 connections in the picture in Pelican. What's it do? How does it make a car smoke when N/G? (I have a feeling one of the connections is intake mfld)? :drive:

[Loren]

Oil Separator

The oil drawn off via the return pumps is fed into "swirl pots". In these containers, the oil is centrifuged and defoamed, i.e. gases which the oil has picked up on the way to the lubricating points are removed. This ensures that the oil always has a good consistency which is necessary to guarantee the reliability of the hydraulic valve clearance compensation. Gases could bring about changes in the engine timing which would have an effect on the performance and exhaust-emission behavior of the engine.

[KevinC]

The original poster is probably referring to the Air Oil Separator rather than the swirlpots. My understanding is that the AOS is part of the system which returns crankcase gases to the intake. It's job is to prevent oil from being fed to the intake along with the gases. When it fails, the engine can smoke badly due to oil entering the throttle body. It's a common failure item on Boxsters. I assume the 996 has something similar. Here's a link to some good info on the AOS in the Boxster: http://mike.focke.googlepages.com/airoilseparatorreplacement