15 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
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YOUR RESEARCHCrankcase vent valve
Reported or suspected cause
valve or the o-ring
Suggestion or failed attempt
No successful repair reported for this finding.
0
Identified cause
1
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0
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Leading evidence: 'valve or the o-ring' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'valve or the o-ring' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Replace / just curious' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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15 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
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Please clear up my confusion. If someone says a 996�s crankcase vent valve has a small leak is that synonymous with the AOS, or a separate part that connects to the AOS?
Thanks
On the 3.4l engjne the aos cross over tube has an elbow with a relief valve. Mine was leaking oil. Not sure if it was the valve or the o-ring. Basically made the rear passengerside wet.
The crankcase system might be different depending on year but as you�re seeing from the responses here, it�s not a great description to use. There is the AOS and there is a small valve on the passenger side of the engine that is designed to prevent excess pressure on that side if there is a problem down the line to the connection with the AOS.
- A failing AOS can leak- The o-ring for the passenger side vent and valve can leak
https://www.ecstuning.com/b-genuine-...e/99610704751/
- The crossover tube from the passenger side crank vent and valve to the AOS can leak
The car in question is a 2002 Targa that was undergoing a PPI yesterday. The mechanic sent the following message along with the attached photo:
"The first picture of the engine from under side is the crank case vent valve leaking. The leak is new. If left unrepaired it will cause big clouds of oil smoke out of the exhaust on start up and will continue to smoke while driving."
My buddy has decided to pass on this car.
^^^ Hmmmm... Hardly a reason to pass on an entire car - are there other issues, too numerous to list ? Too many people think/believe that maintaining these engines is some kind of black art, and that every problem leads to catastrophic failure. While there are issues to be careful of, the fact that a 20 year old piece of plastic with an O ring is leaking shouldn't be that big of a deal breaker...
I actually thought this car was the one my friend would finally pull the trigger on. 85k mile florida based 2002 Targa, manual, with original imsb but with lots of service records. Current owner has had it 15 years and was very forthcoming with information. Post purchase he was planning on paying to replace IMSB, clutch, flywheel, RMS, AOS, water pump, top side hoses, vacuum lines/clamps, & coil packs/plugs. All-in post repairs he would have been in it for approx $27.5-30k. After seeing recent BaT sale of a 996 Targa i didnt think that was a bad level, but he decided to pass and keep looking. I think a big factor was buying long distance and not being able to put his own eyes on it and drive it. Interior condition as documented in another thread was a minor concern as well.
The leak is on the drivers side and I'd bet it's just an O-ring or cracked vent tube. The valve is on the passenger side. Picture looks to be a mirror image (backwards)
