Rear main seal problem...

..on '99 996's - what's the symptom of this, just so I know what to look out for - is it simply excessive engine oil consumption or are there other issues to be aware of?

Look for an oil dripping from the center of the engine where it attaches to the transmission. This seal is between the crankshaft and the flywheel so it leaks out the joining surface betwen the engine and transmission.

Initially you may notice the occasional drop on the garage floor and if you get under the car you'll see the oil trickling down where the bellhousing meets the engine block.My concern when the dealer fixed mine was what did all that oil due to the clutch? Fortunately my seal was fixed the first time and the clutch was like new after 14K miles--2 weeks later I had a transmission failure-but thats another story. PS--a bit of advice--do not under any circumstances own or lease one of these cars without a factory or extended aftermarket warranty. I hope you have better luck than I have.Never again.

This is what it looked like on my car. This is about 10,000 miles into the life of my 2001 996 C2. It shows up nice in the pictures, but it's easy to miss, unless you're really looking for it. Top of the picture is the engine, bottom is the transmission. Another looking towards the back of the car.

Thanks for all the replies, guys! Very useful for a total non-mechanic like me - especially the pictures!

hello, so porsche got you also with a bad engine read my message board and give me some feedback. gerard

Here is what the seal looks like: It is the round black ring (the one that shines on the bottom).. This holds the oil around the crankshaft not to leak out of the engine casing.. I changed mine and now it looks ok. There is no oil under the engine. I also changed the clutch and plate which were slipping due to the oil leak from the seal.. (a lot of white smoke due to the result).. Wael

That is the second generation seal, and this is what it looks like out of the car. Jeff

Thanks for the pics Tool & Waz. Anybody know what the difference between the new and old seals?

Was this an issue for C2 and C4 cars and for Tip and Manual ? Is there any way to check which version of the seal is present in your car ? Regards Cammy

From the March 2000 TSB: A new type of crankshaft sealing ring is being introduced into production as of February 22, 2000, beginning with engine type, M96/04, number, 66 Y 11627. 999 113 476 40 Old style, no longer available. Do not use old stock for repairs. 999 113 490 40 New style

need to check tonight then as I bought mine in Sept 2000, is there a plaque with manufacture date or engine model number ? Thanks Cammy

Engine number is usually on the car title (or other paperwork). It is also on the engine... but this would require looking at the lower left side of the engine block (behind the drivers side rear wheel). You may have to clean the cosmoline off to read it.

on the sticker under the trunk the engine number is M96/04 66Y but the other number says the transmission/gearbox number which is different from the one you quote(mine is a tiptronic). The number 11627 doesn't appear. Regards Cammy

"The number 11627 doesn't appear." 11627 is the first number in the series with the new seal. If your engine number is higher than this... it has the new seal. If it is lower is does not have the new seal.

You were right about the cosmoline, looks like number 19731 . Thanks for all you help. Regards Cammy

Now I am confused?? My engine number is M96/02-68X-G9630-10 I got this from the sticker in the trunk. is this wrong? Should I dig further into the cosmoline and confirm or can someone help me with this.