I guess I had too much time today or perhaps I have always been the curious cat so.... I decided to find out more about the AOS


On the outside, the unit is very beefy. However, I found that inside is a semi-thin rubber diaphragm that is cracked. I am actually amazed that this rubber lasted 62k miles.

Without me being an engineer, I believe that this is definitely a disposable item. If mine lasted 60k, I think I'll replace the new one At around 45k.

I am not saying that the sky is falling, but you guys can decide for yourselves. Me, I don't want to wait for another 1 hour waiting for the tow truck.
Cheers!

 

are there two AOS's in the 997 or just one? I got 85k on mine I think I might need to do this. How hard is it to do?

 

There's only one that I know of (at least the one that breaks resulting to white cloud of smoke).

How hard is it? I give it a 3 even though Pelican Parts gives it a 4-wrench rating. Mine is a 2007 model so there's less stuff to worry about or take apart.

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

 

Also, check out the pic #3 of the article below. Though this pic shows severe conditions, I am supplying the info to let everyone know how oily the intake could be (i.e., just read the last sentence related to Pic #3). Mine was not that severe, but I bet that had I driven it, my car's intake would have accumulated the oil.


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

 

I found these for various Model Year for 997:

#4 in diagram:
http://www.autoatlanta.com/porsche-p...section=104-05

#1 in diagram:
http://www.autoatlanta.com/porsche-p...section=104-10

#1 & #9 in diagram:
http://www.autoatlanta.com/porsche-p...section=104-11

 

#4 (104-05) and #1 (104-10) are I believe for a 996. I replaced #1 (104-11). Read up the PelicanParts DIY article (
http://www.pelicanparts.com/techarti..._Separator.htm
). Also, call up PelicanParts; they are very knowledgeable about which one you'll need.

BTW, it's so unfortunate that the diaphragm could not just be replaced. I bet that the rubber unit would just be <$5.00 to produce --- what a waste!

 

Wow. I have AOS replacement on my list of things to do, but after seeing your photo, I think I'll move it up on list a bit. Will order the part ASAP along with a water pump.

 

Sorry guys but what is AOS? what is it for? i apologize for stupid questions.

 

AOS (Air Oil Separator). For details via reading, see below link. For details via actual experience, your car will emit white cloud of smoke --- you'll see it as if the engine just blew a head gasket.

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




I also looked at the picture again in high resolution. You guys may not see it, but in high res, the 5-6 o'clock area has the most discoloration. I think this area is the primary area where "hot" oil/gases/etc. hit first; thus, the area of failure.