Moved this question from 911 to 996 forum

[Toast54]

As I have been researching 911's off and on, I ran into this...
"We originally purchased this vehicle from another dealer with the understanding that it needed a clutch. We did the clutch and flywheel, but then noticed an oil leak. Porsche knows that 5% of their engines in ’99 have an incorrectly machined block. When you put the rear main seal in, it’s not 100% centered and oil does leak. For the individual who has the resources to repair this engine, this is truly an exceptional deal." Perhaps someone can enlighten me? Are there VIN's to avoid?
Thanks


You would be better off in a 996 specific forum and I believe that a lot of what has been stated is bollocks but; the answer to your question is that Rear Main Seal issues in 996s were random but possible across the series so no, you can't pick specific VINS to avoid.
__________________
Laurence
2008 cayenne GTS | 1998 spec Boxster | 1970 911E Coupe | 1969 912 Targa | Gone but still loved 2004 GT3
New project - 84 coupe with backdate to 70s STish looks, 3.6 motor and a less is more approach (2100# target)

[JFP in PA]

Originally Posted by Toast54

As I have been researching 911's off and on, I ran into this...
"We originally purchased this vehicle from another dealer with the understanding that it needed a clutch. We did the clutch and flywheel, but then noticed an oil leak. Porsche knows that 5% of their engines in ’99 have an incorrectly machined block. When you put the rear main seal in, it’s not 100% centered and oil does leak. For the individual who has the resources to repair this engine, this is truly an exceptional deal." Perhaps someone can enlighten me? Are there VIN's to avoid?
Thanks


You would be better off in a 996 specific forum and I believe that a lot of what has been stated is bollocks but; the answer to your question is that Rear Main Seal issues in 996s were random but possible across the series so no, you can't pick specific VINS to avoid.
__________________
Laurence
2008 cayenne GTS | 1998 spec Boxster | 1970 911E Coupe | 1969 912 Targa | Gone but still loved 2004 GT3
New project - 84 coupe with backdate to 70s STish looks, 3.6 motor and a less is more approach (2100# target)

There is no VIN list, or any other way to predict which engine's RMS openings are sufficiently out of round to cause leaks. Porsche produced a hyper expensive tool to test the engine cases for the correct "roundness" that almost no one has ever seen, much less used. There was an article in "Excellence" magazine about all this a couple years back

In the real world, most shops faced with leaking RMS seals pull the offending unit and replace it with the latest PTFE unit, installing it at a depth of 13MM from the flywheel mating surface on the crankshaft. If that setup leaks, the engine cases are bad and you need a replacement engine.