996 C4S Multiple "transmission replaced" on Carfax

I'm looking at a C4S that has an unusual set of entries on the Carfax. In March 2004, September 2004 and March 2005 there are logs for "Transmission replaced". Then October 2005: Failed emissions inspection Transmission removed and reinstalled Front crankshaft oil seal replaced Transmission checked Passed emissions inspection It has since only added 6k more miles to the odometer. Other than the fact that the car has only done 6000 miles in 19 years (which the more I think about it, yikes), does anyone have any interesting thoughts around the transmission situation?

Carfax is pretty generic. It could be that it was entered as replaced when really it was just removed and reinstalled. Either way it�s strange that was needed. But three transmission replacements is nearly impossible in that timeframe.

Yeah, it was a common service item back in that era that revolved around a leaking rear main seal (RMS). The leak was a byproduct of a weak RMS and potential lack of alignment between the engine and trans. The good news is they eventually found a robust RMS that solved the issue. About that time they also started to recognize the IMS issue of which solutions were developed to solve the issue as well. The RMS procedure included removing and reinstalling the trans to measure the alignment using a tool known as the "go-no-go" tool. If the alignment was out of spec, they would replace the entire engine. I dont remember if you would get a new trans as well. But if it was NOT out of alignment, they would just replace the RMS. All this was done under warranty and it was no big deal at the time. Just a series of procedures to fix a slow drip every so often that wasn't catastrophic. Don't know how many trany drops, engine drops and engine replacements they did during that era, but as you can imagine, it cost Porsche alot of money until they figured out they just needed a better seal (RMS) which they eventually found. Sounds like the previous owners had the car serviced during that era which is a good thing. From my experience, the 996 engine and trans are very durable on the street and track if they have been properly serviced over the years. If you are interested in the car, what i would do is get every service record you can to see what was done and when. This will tell you what you will have to replace and service when you take possession. Just as important, i would find a great Porsche Indy that specialized in the 996 and have them perform an invasive PPI which includes dropping the sump, checking for debris, scoping the bores from the sump for borescoring, etc. The 996 really is an incredible car. The key is finding one that has been well serviced, which includes all of the RMS and go-no-go servicing back in the day. This doesn't scare me, in fact it actually would encourage me to look deeper at the car since original owner had it properly serviced in 2005. Good luck with it. I hope it's a gem!

100% what GC996 said. The CarFax on my 2002 C2 also has the same service notes 2004 and 2005 at ~9000 miles. While I have spent a fair amount on this buggy, I have had no problems and nothing leaks.

I would have to check my service records, but I wouldn't be surprised if the Dealer didn't remove the trany at least 4-6 times over that time period in my car. Every time there was a leak or a new RMS introduced, I was at the shop having them do the work under warranty. Sure, some owners probably didn't pay attention to it bevause it was a lease and they were going to give ut back after 3 years, but other like me planned on keeping it for the long haul, so I paid attention to any leaks and announced parts updates. It also helped that I got an extended 6 year warranty. But i wasnt the only guy with one. The dealers sold them like hot cakes. FWIW, here is something else to think about, the Porsche recommended oil change interval at that time was a crazy 15k, which certainly wasn't good for bore wear. Especially if you lived in a cold weather town and did alot of short grocery store runs without getting the oil good and hot. Owners that were at the Dealer upgrading their RMS under warranty over that time period probably never went 15k on the same oil. That's bonus points.

*^^^There�s no real need to change the oil if you�re only changing the RMS (there�s only oil there under pressure when the engine is running). I wouldn�t bet that the dealers changed the oil out of the goodness of their hearts - after all, the company line was 15k mi. on Mobil One. Unless there�s a service record that specifies �Oil & Filter Change�, I�d assume it wasn�t done�

Sure, anything can be possible. Mine did. But to @dporto point, you only really know what service has been performed and when if you have the service records. Oil tests, looking thru the sump and oil filter, borescope, etc with an invasive PPI can help confirm the condition.

I�ve had some �less than stellar� experiences at a local dealership, so I�m always skeptical!

I hear you. It's case by case. My dealership at the time had a great service team that were heavy into porsche motorsports and the issues. No question I lucked out.

Really great info, thanks for the feedback.