Got my car back and all is good. AOS was the issue although I still feel the smoke was white not blue and I guess Mobil 1 burns sweeter the dino oil Thanks for everyones help.

 

quick question, does an AOS failure also result in CEL fault?

 

Yes a CEL was triggered with my AOS.

 

Oil being sent to the combustion chambers will cause a "random misfire code". With the oil being burnt off it will cause misfires instead of a clean burn. Oil smoke has always looked white to the average driver. You have to really be in tune to what "blue" smoke looks like.

I just went thru a AOS issue with my car. She ran perfect, no smoke what so ever, but I had a CEL for random misfires. Changed plugs, coils, then Pulled the intake apart and there was oil pooled in the crossover......volia....AOS!

 

Found this article:

The Engine oil air separator directly affects the engine crankcase atmosphere because, basically, all Porsche's from 1980 on, including the current 986, 987, 996, 997, Cayman & Cayenne engines, all are positive crankcase type systems. This means that the engine crankcase has vacuum supplied from the intake manifold to collect and burn the residual combustion by-products or blow-by in the crankcase by running it through the engine again, all in an effort to lower the vehicle tailpipe emissions.

On most occasions when the oil separator fails, the low pressure (vacuum) in the engine crankcase rises to an unusually or abnormally high figure and, more likely than not, it ends up drawing engine oil into the intake system. This usually fouls spark plugs and, in rare cases, causes damage to the oxygen (O2) sensors, catalytic convertors and, possibly, various other sensitive fuel injection components. In extreme cases an oil separator failure with excessively high vacuum can actually cause the rear main seal to make noise, i.e. "honk".

Interestingly enough, the only way to test the oil separator is to periodically test the engine crankcase vacuum with a water filled Monometer (aka: a Slack Tube tester), which is an ultra sensitive vacuum gauge. On BMW's and Porsche's, the engine crankcase vacuum is normally around 4-6"� (inches) of water. When oil separators fail the crankcase vacuum can rise to the 8-12"� range and even higher, depending on the extent of the failure.

When the oil separator starts to fail on Boxsters (986 & 987), you generally start to see a substantial amount of smoke from the exhaust tailpipe. When the oil separator completely fails, the engine exhaust smoke can reach dangerous proportions. You'll think your Boxster has turned into an anti-mosquito smoke machine.

When the oil separator fails on 996-997s, it usually does NOT create the same exhaust tailpipe smoke as a Boxster. It is almost like being a silent killer (and a costly surprise).

Sometimes when an oil separator fails, it can cause the Check Engine Light (CEL) to come on. you may not be experiencing any other symptom, but the CEL should get your attention. This condition should be checked out with the Porsche factory PIWIS tester. It is important to see exactly what is going on. Otherwise, you're just guessing.

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I don't think you need to go with a monometer but rather buy a vacuum gauge from Autozone or Napa.

http://www.suncoastparts.com/product...=CarreraSSport

 

Where on the crankcase is the vacuum test take-off (on a 997.2, etc)? I"m assuming it may be a capped pipe.

 

Little help here. Seems the AOS is failing already after 2500 miles and 3 months. Is there any history of these failing so quickly? Anything else I should look into that may be the cause to this issue?

TIA
Dave