DK570

Hi All,

I've known about a small slow leak near the back passenger area of the engine for some time. While I was having my summer tires mounted, the dealer said it was the crankcase ventilation elbow, and needed to be replaced. Has anyone ever done this themselves? I assume you can access it with the airbox out, but I'm not sure, and haven't gotten a chance to look since it's been raining so much.

Imo000

Many has, look for Air Oil Seperator or AOS.

rb101

That elbow is connected to the AOS. Your AOS is bad and blowing oil out that vent. Replacing the vent will not fix the leak.

DK570

I haven't done anything about this yet, but I now think the AOS may be indeed on its way out. The last two days the mist has gotten significantly worse, so much so that I can see small mist spots on the back bumper. Looks like while driving at speed, the mist is being caught by the back pressure and deposited on that corner of the bumper. Also, now a definite spot on the driveway. The oil filler cap can still easily be removed with the engine running. However, with it removed, I hear a hissing sound, and the engine runs rough. Can't remember if that happened last time I checked. Also, I don't see why it would matter, but the last two days have been the warmest by far this year. Any ideas what a AOS should cost at a dealer? (6 speed C4 cab)

Zapna

I have the exact same problem. The oil separator is $121 at my local pcar dealer to an individual. $102 to a shop. I am having mine replaced by a local indy as you have to drop the engine about 6" (I'm told) to get the bugger out. My indy is quoting about 4-5 hours. Ouch! Did you resolve your problem yet?

DK570

The dealer replaced the elbow and the line leading to it, still have the original AOS. So far it seems to have worked. Since I was uncertain of the origin of the leak, I didn't want to do it myself. I figured if the dealer did the diagnosis and work then if I drove it for a week and it started to leak again I could go back and say "hey, this still isn't fixed, make it right". Whereas if I did it and it started to leak again a week later I would have to spend another weekend diagnosing/replacing, and not driving. Luckily, it's been all good.

pecto3

I'm having the exact same leak for the past 3 years now, not getting any worse yet. Do you happen to have the part number of the parts dealer replaced? Thanks!

Imo000

Might be the same area but your leak could be from a different spot/part. Dignose it and take it from there.

DK570

I'm not certain of everything that was replaced, but I believe if you look at the diagram here:
http://dcauto.gotdns.com/illustration/index/455263628
probably numbers 7,6,4,22
It looks like a real pain to get in there. I wish Porsche made it more accessible, but at least it's not as bad as the 991. Seems like for that you need to take the rear bumper off to do almost anything - filters, plugs, belt etc. It looks so discouraging, I will probably never buy a 991. With the 996 you can quickly take the airbox out, and reach a lot.

DK570

To update this, I'm still having the problem. Dealer replaced once, seemed to be good for a while, but then started leaking again. Dealer replaced it again (for free under the genuine parts warranty). Now it's leaking again. Over the winter, the AOS was replaced, so I don't think that's the issue.

GLIDE

Agree with this.

The cam position sensor is right there also. Has an o-ring. Not bulletproof. Pita to get to that one.

Does you oil pressure present anything strange?