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I have a 2005 997S. It suffered bore scoring before I owned it and the engine was replaced in 2014. I called the dealer that did the work and they assured me that in 2014 they would have used the newer 2006+ short block.
The serial number on the block is M97/01AT44600908 (see attached). According to this thread after the AT it should be 68 not 44 so that is confusing, but the 6 would imply it is model year 2006 M97/01AT44600908 and therefore the newer block / IMS.
@Daniel Kant If you look at my photo you will see that only M97/01AT was engraved at the factory. It looks like the dealer stamped the 44600908 on the end.
Last edited by rupes; 07-06-2020 at 12:19 PM.
Reason: Correct information
Sorry to bump an age old thread. I have read a lot and tried my best to decode, but hopefully I can get a quick response from someone who is smarter than I.
I am looking at buying a 2005 997 C2s, manufactured in 2005-04-01.
The engine code reads: M97/ 0168512053
From what I gather, engines produced in 2005, some of them were updated with updated IMS, some were not. Is anyone able to deciper based on this engine code which IMS this car has?
Sorry to bump an age old thread. I have read a lot and tried my best to decode, but hopefully I can get a quick response from someone who is smarter than I.
I am looking at buying a 2005 997 C2s, manufactured in 2005-04-01.
The engine code reads: M97/ 0168512053
From what I gather, engines produced in 2005, some of them were updated with updated IMS, some were not. Is anyone able to deciper based on this engine code which IMS this car has?
For M97 S motors, engine serial #s from M97/01 68509791 forward SHOULD have the larger revised IMS bearing, but note how I emphasized the world should. In the 05 model year, the only way to know with 100% certainty which bearing is in the car is to inspect the nut on the IMS bearing flange - larger nut = larger bearing. I believe in 06-08 you have to pull the transmission to do this inspection, but think Jake Raby mentioned that for the 05 model year, there's a process and trick with a boroscope camera where it can be done without pulling the trans.
IMS Bearing Flanges - larger on the left, smaller on the right
For M97 S motors, engine serial #s from M97/01 68509791 forward SHOULD have the larger revised IMS bearing, but note how I emphasized the world should. In the 05 model year, the only way to know with 100% certainty which bearing is in the car is to inspect the nut on the IMS bearing flange - larger nut = larger bearing. I believe in 06-08 you have to pull the transmission to do this inspection, but think Jake Raby mentioned that for the 05 model year, there's a process and trick with a boroscope camera where it can be done without pulling the trans.
IMS Bearing Flanges - larger on the left, smaller on the right
Thanks a lot for this information. The car is at a dealer, and I would be curious if I can get them to inspect the flange for me.
If you come across the link for that technique that Jake mentions, link it here, I will also research the forums for it to see if the dealer can help do this at the PPI.
This is incredibly helpful, concise, and easy to understand. Thank you, I've been going blind in various forums trying to get this exact detail.
One question. I haven't been under my 997 yet, is the IMS bearing nut flange visible without removing anything? Thanks,
Traditionally, no, you had to remove the transmission, but I think Jake Raby has come up with a trick on the 05 cars to be able to see the bearing flange nut without taking off the transmission, but I don't know what the trick is. I believe on the 06-08 cars, you still have to remove the transmission.
I saw that post by Jake and have been wondering about the trick. The only thing I could come up with was pull the starter and snake a camera down there. Doesn't sound like a very good way to do it but how else can you see the nut without removing the transmission? Plus doesn't the flywheel cover the bearing flange? It must be a pretty good trick.
This can be done with nothing disassembled. The key is a bore scope with a head of no more than 5mm diameter. There's only one way to do it on the manual cars. The tiptronic is easy, as they have a rubber plug that's removable from the bottom of the gearbox, allowing direct access.
Hi everyone, I am coming in late on this thread, but I was hoping I can get help in decoding my 997.1 engine's serial number .... Thanks
M97/01AT68866501
The AT in that serial number means it's a replacement engine that Porsche installed. Means the original motor failed and was replaced by a new one direct from Porsche.
The AT in that serial number means it's a replacement engine that Porsche installed. Means the original motor failed and was replaced by a new one direct from Porsche.
Many thanks, greatly appreciated. Do you think the IMS bearing on this replacement engine is the “large" modified one?
also one more thing please, is this a 2008 engine? am asking because the Carrera S I just purchased last week is a 2007! According to the registration papers.
11-05-2018, 03:58 PM
