Remembering why I
dislike working on
AO Silver Member
Join Date: Sep 2001
Re: Black jobbie
It's an oil seperator. Oil fumes from the crankcase goes in, whizzes around to try and persuade the larger particles to condense out, the liquid drains out the bottom and back into the sump (and is supposed to go to a small fitting near the cambelt end of the rear head low-down, not atmosphere) then whats left gets sucked into the intake and burnt.
Sometimes called PCV - positive crankcase ventilation. Some engines rely on this oil mist to help lubricate the top of the bores a bit as well. Couldn't tell you if the V6 does or not though.
Main reason it fills with cack is condensation forms a nasty sticky emulsion. There isn't much inside it, just some carefully chosen bits of metalwork to encourage the mess to whizz around and separate.