Engine number vs IMS bearing

[Julien]

Hello everyone,

I am in the process to acquire a 997 2005 and I would like to confirm the following:

Engine (3.6) number up to M96/05 69507475 has the older IMS bearing (do not buy!) and Engine number from M96/05 69507476 has the larger revised IMS (you can buy!).

Thank you.

Julien

[JFP in PA]

Sorry, but the engine numbers, like all of the other supposed ways (VIN, date of build, etc.) to identify which style bearing is in a 2005 is useless. Every method, other than taking the car apart and looking at the bearing center bolt, has proven to be wrong many times over.

And as for which bearing is preferable, the older serviceable unit or the newer one that cannot be removed without tearing the entire engine apart, well that is a matter of personal preference. The older bearing can be replaced and eliminate the possibility of failure, the newer bearing (which also are known to fail) does not give you that option. If it were me, I would want to retrofit the bearing.

[Julien]

I have a bill on which it was asked to verify the IMS. It is mentioned that based on the engine code, the bearing is already upgraded...

So, it does not help to have no worries about IMS issue?

[JFP in PA]

The only way the engine code would indicate that the car carried the last design bearing would be if the engine number contains the letters "AT" and the engine number itself decoded to being a 2005 or later engine. AT means the engine is a replacement, all of which after 2004 are the last design bearing.

Just be aware that (1) Porsche never retrofitted an engine with an aftermarket IMS bearing, (2) As I mentioned above, the final design bearing fails just like the earlier units, and (3) The only IMS bearing you don't have to worry about is one that has been retrofitted with an LN Engineering replacement.