Mark Dickey

Hello all,

I was hoping to do a full AOS reseal before I installed an aftermarket catch can. Does anyone have a lead on where to get a replacement lid seal? Is it the one that sandwiches between the six lid mounting tabs and the AOS body (see image). Porsche only sells the entire AOS system so there is no individual part number for the seal. I know enthusiasts used to buy an aftermarket seal from Mcmaster part number 9396K172, this however is out of stock/NLA. Any other leads? Might be a long shot but I appreciate it (:

Sam Lin

This old post mentioned the size code as well as dimensions, should make it easier to find a replacement from a hydraulic supply shop:

huskeric

See this thread... he had extras and sent me one for free

https://rennlist.com/forums/924-931-...-question.html

944M3

Would a bad AOS lid o-ring lead to oil in jboot and throttle body?

I changed o-rings where it attaches to block and did the dipstick one but literally until today, did not know there was an oring at the top lid. (not talking about the yellow oil cap lid).

After doing a complete engine reseal job, except for this oring, I’m getting a ton of oil in jboot.

AOS I believe works with engine vacuum. So I'm assuming a bad oring would allow air in/into the AOS (via suction). If that is correct, would a lathering of RTV silicone around the rim of the outside of the cap also act as a seal?

Trying to understand how bad orings anywhere in the AOS leads to oil into intake track.