gtntahg

Well, here's a softball for you:

What is the function of the Air Oil separator?

Where in the engine compartment is it located?

Is it strictly a mechanical device or does it have electronics like a mass air flow sensor?

And, more importantly, does the motor need to come out to replace a failed one?!

Thanks in advance

Louis de Funes

What is the function of the Air Oil separator? - The engine air-oil separator is an emissions device that is responsible for collecting residual gases and vapors contained inside the crankcase and funneling them back into the intake manifold where they can be burned in the combustion chamber. This reduces the overall emissions of the engine.

Where in the engine compartment is it located? - on the right side of the Engine in the back behind the throttle body and plenum [URL="http://www.pelicanparts.com/techarticles/Porsche-996-997-Carrera/09-ENGINE-Air_Oil_Separator/09-ENGINE-Air_Oil_Separator.htm"]

Is it strictly a mechanical device or does it have electronics like a mass air flow sensor? yes it has no electronics in it - I had mine replaced and kept the old one

And, more importantly, does the motor need to come out to replace a failed one?! it is easier to get the job done with the engine out but it it also possible to do it with our the removal of the engine - it is just very labor intense


Here you can read more about it :

http://www.pelicanparts.com/techarti..._Separator.htm

Rikky001

Louis de Funes has said it all already. and with the good Pelican link.

Just disagree that it is labour intensive. The first time it took me 4 hours to exchange my AOS and starter/ alternator cable, now I change the AOS within 2 hours and ample time for a few beers in between.

Most people exchange the AOS together with a starter and/ or alternator/ starter cable replacement to save labour hours.

Not the most fun job but easy DYI with basic tools.

Edgy01

We used to call them PCV valves years ago--positive crankcase valves.

platinum997

Anyone just eliminate the AOS/PVC and go to a catch can setup? Much more serviceable and keeps the gunk out of the intake manifold.

I have done that on other cars with good success. Not sure on a M97 or 9A1.

gtntahg

Ah-ha. PCV valve. That I understand.

And a remote oil catch can in place of the AOS would work well, I would think, for all the reasons just mentioned.

DC911S

Good luck finding any room in the engine bay for a decent sized catch can, and they have to be drained as well. Plus lots of them out therer are junk. Some places make really god ones.

platinum997

Given the nature of the 9A1 DFI, I would think a catch can would really help. With DFI, you don't get the cleaning effect of gas on the valves. Removing any possible oil contamination I would assume is beneficial.

What's the typical life of the stock AOS?

If it's not electronic (most are not) how do you know it's faulty?

JCD911S

White plumes of smoke from exhaust and/or strong vacuum suction through oil fill tube while running.

Rikky001

The AOS is just a "catch can" but is less stupid as it is heated by the cooling water.