slowslowcar

Looking to buy a 996 and the owner says they wanted to replace the IMS when doing the clutch, however, "the mechanic found that the engine was replaced already with seals IMS?"

pic of the block:


post a picture

Weazer

Maybe he meant that the replacement engine has the third generation large single row IMS bearing that cannot be replaced without spitting the engine cases or boring out the IMS bearing opening?

4Driver4

More like landlocked? Boxstered in? Internal? Encapsulated? Trapped?

Chodey

You buying the other guy's car?

hatchetf15

OP - That serial number is only 213 numbers from an M96/01 engine rebuilt in 11/04. Most sources say rebuilds in 2005 have the newer unserviceable bearing. No one, not even Porsche, can guarantee which bearing is installed without a visual inspection. This engine pictured is likely a 2005 rebuild of a 99 3.4. But I’ve never found any reliable info on how to find when a reman was actually built, how many built per year, etc. So, was the IMS bearing nut visually confirmed to be the 22mm nut? If so, then the IMSB is the unserviceable large bearing.

DBJoe996

Well, if anything, the AT in the engine number means it is a replacement engine. Now Porsche did do a few rebuilds, but not many. Most of the time they just replaced the entire engine. If it is a replacement engine from 2004, it has the larger non-servicable IMSB. The failure rate of those is astronomically small. Proper oil/filter changes at 3-5K intervals and you are good to go.

Sealed IMSB means it has the bearing seals on both sides. Not really a bad thing. Next clutch change, pop the external seal on the IMSB. That's it.