AOS replacement w tranny out ?

[Capecod 02/4S]

Can anyone point me to directions on how to replace the AOS on a 02 996 4S? Replacing IMS, RMS and Oil Cooler and good to go on those but figure I may as well do AOS if I can at the same time. Thanks

[tonythetarga]

There are a list of Tech articles for many models including the 996.
Porsche 911 Air Oil Separator Replacement - 996 (1998-2005) - 997 (2005-2012) - Pelican Parts Technical Article

[JFP in PA]

Changing the AOS with the trans out is quite easy, all the stuff you cannot even see when the car is assembled is right out in the open and easily accessible. What takes the average DIY'er hours with the car together, takes about 15 min. with the gear box out of the car.

[Capecod 02/4S]

I can only see one screw which appears to be an allen head. Are there more on an 02 4S? Seems odd only 1 screw would secure the entire unit. It's difficult to see or tell how some of the hose connections are made, some cleary have a metal clamp but a couple otheres I have no clue. Any help would be greatly appreciated. Just installed the new LN IMS, will do oil coller tomorrow and RMS upon arrival. Kinda want to pull out the AOS prior to ordering a new one in case I need any hoses or other parts but it would be nice to look over the new one prior to pulling out the old one too!

I tried the previous link as suggested but find very little detail or tips re AOS replacement. I learned a great deal (mostly from my mistakes or lack of directions) doing this work and will post it upon completeion as I'm sure I can save many the hours of the frustration I experienced with a few good tips/suggestions.

[JFP in PA]

It is held in by two bolts.

Only the large bottom hose is held by spring clamps, the smaller hoses are push on connectors that must be pinched by two fingers where the serrations are on the outside collar ring; this will deform the collar just enough that the hose can be pulled off. Do go nuts, just press it in a bit.

[Capecod 02/4S]

Thanks for the help. Can you tell me where the 2cnd bolt is located? I only see one nor do I see a second on the parts drawing. I've gone so far as to look behind it with a borscope and still can't find it.

[JFP in PA]

one bolt is directly above the other:

[Capecod 02/4S]

Originally Posted by JFP in PA

Changing the AOS with the trans out is quite easy, all the stuff you cannot even see when the car is assembled is right out in the open and easily accessible. What takes the average DIY'er hours with the car together, takes about 15 min. with the gear box out of the car.

I don't follow! I can't even see that back bolt and can't imagine being able to loosen it never mind replace it. My engine is in and manifolds on, just have tranny off to do IMS & RMS. I see some pipes to the right of the AOS while I'm facing the flywheel near the inner rear fender, i think larger one to the right is coolant and if I can remove those maybe I can get to the bolt. Otherwise I cant imagine doing it without removing the manifold. IMS and RMS are done and I'd like to continue but I'm just not sure what to do at this point.

[JFP in PA]

If you rotate my image 180 degrees around the axis of smaller of the two outlets facing you in my photo, you have your image. The other bolt is behind the AOS. 1/4 drive extensions and wobble sockets are the tool for the job.

[Capecod 02/4S]

Seems maybe there are hoses or wires on top of it. Should you pull the hoses first? I figured why waste my time if I couldn't loosen up the unit anyway.

I replaced the oil cooler this afternoon, that was a bit of a ***** too but I'll be damned if I can see that second bolt.

[JFP in PA]

I always get all the hoses possible out of the way first, just to make room.

[Capecod 02/4S]

OK, i'll give that a go tomorrow! Thanks for your help & input.

[Capecod 02/4S]

Thanks for the help. Finally found the little bugger, it was a 5mm allen head hidden below some wiring. Actually got about a 6 in long 1/4 drive extension with allen socket to miraculously fall into place. I didn't know you could pull the hoses out in a bunch which turned out very helpful as I broke the top nipple off and it was lodged in the hose. Never could have gotten it out in the the engine, gave me a great opportunity to clean them up and inspect them too!

[JFP in PA]

There are several items on these cars that are akin to building a ship in a bottle, you just met one of them.