If the truth be known, I believe that most Porsches leak oil. So, those of you that have bone dry bottoms on your cars should be extremely thankful.
Having owned 911's as well as 944's and (2) 968's, I can tell you first that every one of mine leaked oil! The problem is more prevalent with the 911's and also usually harder to fix when the leaker gets too bad.
The history behind cars that do not leak has to usuallly be that the previous owner stayed on top of correcting leaks as they occurred. Which is going to be my objective with my current car.
There is also an issue with running synthetic oil in cars that did not start out life on synthetics. When Mobil 1 was first marketed (I was a Mobil employee at the time), there were a slew of claims against Mobil for engine repairs for leaks that only occurred after changing from fossil oil to synthetic. When my company looked closely at the issue, it was determined that the additive package in our Mobil 1 was successfully dissolving oil "sludge" that had accummulated over the years. In all reality, the seals were probably already gone in these cars, but the sludge buildup was enough to plug any leakage path.
So, many of the 968's that have been converted to synthetics may be experienceing the same problem. The good news is that if you replace the failed seals, I doubt that you'll ever have a leaker in the immedicate future.
So, suck it up, and begin replacing the seals. Most of the seal replacements are within the capabilities of a weekend wrencher. I think that it would be difficult to spend more than $400 to replace every seal in the 968 engine. Labor, on the other hand, is the kicker.
I think that oil leaks are more prevelent in engines that are made of alloy, since alloy engines grow much more thermally with heat than do iron blocks and heads.
The only seal on the 968 that appears to be a "challenge" is the rear main since you have to pull the clutch and flywheel to get to it; and when you are in there, space is at a premium which can make the job annoying.
