While waiting for the VOS in my
Cayman
to be replaced under warranty, i wonder why i found so many threads, here and in other foruns, about the VOS deficiencies in water cooled Porsche's, since every other cars from different manufactures don't have this 'known' issue albeit their cars also do have some kind of VOS.
Why? Is it got anything to do with the boxer engine layout?
No, not really anything to do with the Boxer design engine, rather everything to do with the quality, design and manufacturing of that particular part. I suspect two problems:
1) Design - As designed the part isn't up to the task under stressful situations, like track use.
2) Quality - As built the parts have had diaphram failures or haven't performed as expected for whatever reasons.
Since Porsche had proven parts on the shelf from the 996 series and motorsports parts, the change to the 987 part must have been either to save money or to accomodate space requirements in the engine bay more easily. Since we've seen that the motorsports part can be fitted with some modification to the bracket for the air pump, I suspect it was all a cost-savings issue. Porsche went with a just good enough design made from just good enough parts that when stressed turned out to not be good enough.
AFAIK no one has ever gotten a warranty claim paid by Porsche for this and there isn't any recall with the NHTSA or even a service campaign so either not enough people have complained to NHTSA or Porsche has managed to sweep it under the rug so to speak.
It's a shame that auto makers (like Toyota) have not said "There's a problem, let's fix it" vs. "There's a problem, what's the least expensive action we can take?". Obviously for Toyota they gambled and lost and are going to be out a lot of $$$, so far Porsche has escaped this outcome, most likely because no one is dying over a VOS failing.
Hi K-Man,
We are not talking about a special hi-tech device (far from it), at least none that other mass market brands don't manufacture and use in their cheaper cars with NO problems. So, where is the bug?
Is the Gen II CS prone to the VOS issue or was this one of the improvements?
I don't know about the CS, but mine is a Gen II 2.9
Cayman
and it will have the VOS replaced to see if a bad VOS is the cause for the heavy exhaust smoke upon cold start-up.
I have not heard that they are, but I haven't personally looked at what the equivalent solution is for the DFI motors, but again, haven't heard of any problems reported.
Exactly where is the VOS located and what are the symptoms when it fails? Does it fail instantly when it fails or does it happen over a period of time?
There is a article about that here. It answers all your questions and has links to other threads and discussions on the topic.
Installation of Improved Vapor Oil Separator - Articles
