Replace the air-oil separator

Cited source accounts

After my AOS was replaced, I had the same problem . The MAF sensor was removed and cleaned, and that fixed the problem. This was done twice, once when the AOS was replaced, and about a week later when it started to idle irregularly and I got a CEL.

Replaced AOS, getting misfire+codesreported fixed

Another (possibly cheaper) solution is the Ultimate AOS ( Ultimate AOS ) rather than the Motorsport AOS. While I have a 996 rather than a 987, they also suffer from the same issue. I went with an Ultimate AOS with the Extreme track duty drainback and it resolved my issue, while a mate was having a similar problem and had his car booked in to get a Motorsport AOS installed due to his having the same symptoms, onl

Big oil cloud on cold start (AOS replaced)(987.1 S)reported fixed

I had the same problem and replaced the AOS and now the problem is gone

997 blue smoke on start upreported fixed

I know i once read a thread on measuring crankcase pressure to check AOS but could not find in in my search. I decided to buy a second oil filler cap so to hook up my manometer and check pressure. Here is what I got: 1. At cold start up the pressure was 5.68 in WC 2. After idle for 5+ minutes it was 5.37 in WC 3. After bringing engine to operating temp (water just to temp but still not driven for extended period of time) it was

Another AOS questionunresolved · Original poster

I recently had the AOS replaced "while we're in there". Now my beloved '99 runs discernibly better! Is the improvement my imagination or does AOS functionality degrade over time and adversely affect performance accordingly? FYI-the car has never "smoked"...still doesn't. relinuca

AOS degradation?unresolved · Original poster

I just completed swapping out my old AOS for a new one. It's actually a very straightforward process on the 987.2, I think a lot of the reported difficulty must be from 987.1 models. Unfortunately, swapping out the AOS didn't help the situation; I'm actually measuring even more vacuum at the oil cap at around -61 inH2O. I went ahead and replaced the easy crankcase breather hose with no change. The

AOS replacementunresolved

questions: 1. Does the large puff of white smoke at high rpms mean something different from a large puff at startup? 2. What are possible culprits? I'm seeing AOS and cracked heads as possibilities. Ways to diagnose each? No check engine lights or rough running. 3. What color should the coolant be? One possible problem would be intermix, right? And that would show in the coolant tank. But I don't know what color it should be. Oil looked fine when I took it out. When I get a chance I will get a picture of the coolant.

smoke/aos/coolant questionssuggestion · Original poster

Easy to remedy...but hard to find. Did you chase down the fix? Nice to know that you didn't have to replace your AOS.

Pretty sure its the AOSsuggestion

So could I then do this with an AOS of dubious condition and have a working system? I guess I would need to make certain no dirt has gotten past the diaphragm (if that is broken) or at least clean the innards?

The "Ultimate AOS Solution"suggestion

Source-mentioned parts

98710794700

I wanted to post a DIY on installing the porsche motorsports AOS , part number 98710792600. I could not find a DIY for this install anywhere on the forum. All the old articles/links are broken, so here we go! Parts needed: 987 107 926 00 - 987.1 Motorsports AOS 987 107 947 00 - Vent Line from crankcase to AOS 987 107 946 00 - Y hose from intake plenum to AOS 900 067 316 02 - 6mm x 35mm bolts (need two) I'll go over some

Original source

98710794600

I wanted to post a DIY on installing the porsche motorsports AOS , part number 98710792600. I could not find a DIY for this install anywhere on the forum. All the old articles/links are broken, so here we go! Parts needed: 987 107 926 00 - 987.1 Motorsports AOS 987 107 947 00 - Vent Line from crankcase to AOS 987 107 946 00 - Y hose from intake plenum to AOS 900 067 316 02 - 6mm x 35mm bolts (need two) I'll go over some

Original source

99610792600

of consistent blue smoke is just coincidence with the compression test...? Anyway, I've got oil residue on the plenum body, mainly LHS. All pointing to faulty AOS/ VOS. Would this cause the blue smoke on start up, back pressure sucking oil back into chamber when stopping engine? There's NO smoke under load or WOT and clears after 1-2 minutes, it's really just 1 big puff, and 100% blue, not white. Also has anyone replaced the stock AOS with the larger motorsport version, part number 996 107 926 00? Is it a straight sw

Original source

99610702651

Hey there. I'm waiting for my manometer to get here. Will be here tomorrow. In the meantime, Im curious how this AOS works, just for curiosity's sake. I also picked up my new AOS today. Its part number is 996.107.026.51 I've been examining it, trying to figure it out. I know the two smaller connections on the top are the coolant lines and I've tested vacuum on those and its good. The bottom funnel where the hose gets clamped to is the oil return line to the crankcase and

Original source

98710792600

I wanted to post a DIY on installing the porsche motorsports AOS , part number 98710792600. I could not find a DIY for this install anywhere on the forum. All the old articles/links are broken, so here we go! Parts needed: 987 107 926 00 - 987.1 Motorsports AOS 987 107 947 00 - Vent Line from crankcase to AOS 987 107 946 00 - Y hose from intake plenum to AOS 900 067 316 02 - 6mm x 35mm bolts (need two) I'll go over some

Original source

90006731602

I wanted to post a DIY on installing the porsche motorsports AOS , part number 98710792600. I could not find a DIY for this install anywhere on the forum. All the old articles/links are broken, so here we go! Parts needed: 987 107 926 00 - 987.1 Motorsports AOS 987 107 947 00 - Vent Line from crankcase to AOS 987 107 946 00 - Y hose from intake plenum to AOS 900 067 316 02 - 6mm x 35mm bolts (need two) I'll go over some

Original source