I have a customer claiming that there were two variants of the n/a 997 Carrera S 3.8L motor - one of which has a "small bearing which is easily serviced" and one with a "larger bearing that requires the motor to be cracked apart"... I have no knowledge of this and hes not a mechanic (just restating something his mechanic told him.

Are there two variants of the 3.8L motor and if so, how can i find out which engine a car has if i know the engine serial number? Any idea which "bearing" he is referring to as far as "servicing/replacing" goes? thanks for the help!

EDIT: possibly intermediate shaft bearing size difference?

 

IMS bearing. Two possible variants for MY2005. Not clear if it only applies to 996 or some 997's. MY2006-08 all have the same style.

IMS 101: http://www.imsretrofit.com/ims-101/

Which IMS Bearing Do I Have?: http://www.imsretrofit.com/what-ims-do-i-have/

 

tahnk you for the information... So which one is easier to rebuild if a preventative replacement is being considered?

Edit: got the link to work..Ok from the website it says this:
"There may be some MY05 vehicles with the updated M97 IMS, which is not serviceable, which require a complete teardown of the engine to perform an IMS Upgrade. All MY06 through MY08 engines will have the larger single row ball-bearing identified by the larger 22mm nut."

If I am looking at a MY05, how would I know if it has the serviceable IMS, or the updated M97 IMS which is not serviceable? Also, if it has the updated M97 IMS, would a IMS failure be far less likely, or still a concern?

 

to figure out how to tell by looking, maybe research the LN site? theyve got to at least have something on there that can help you.

http://www.lnengineering.com/

 

Thanks, didnt find anything on there.

I did look at the serial number stamped on the block and have the car up in the air now if anyone knows how to visually identify the versions of the IMS. Thanks!!



"The intermediate shaft found in the M96 and later M97 engine was revised three times. The earliest design incorporated a dual-row ball-bearing used through model year 1999 and in some 2000 and 2001 models. Starting in model year 2000, a single row ball-bearing with a significantly reduced load capacity was used. By model year 2002, all engines used this smaller, lower capacity bearing. Starting with the 2006 model year, the design was again revised to use a much larger single row bearing with the same load capacity of the early dual-row ball-bearings. In all revisions, a sealed ball-bearing was used, rather than allowing for engine oil to lubricate and cool the ball-bearing. There is no recommended service interval for these bearings nor provisions for their replacement from the factory."

I just need to know if I can tell which version my customer's car has by a visual or by the serial number, etc.

 

this discussion may help you

http://forums.rennlist.com/rennforum...tion-date.html

 

Thank you very much:

https://www.6speedonline.com/forums/9...nual-cd-2.html

"The information on the IMS/engine number were extracted from the 2005/06 workshop manual. The info is on page 426. I believe you can still get a copy @ 997 6speedonline. As for manufacture date, there is no way to tell, same as for a VIN."

"To determine if your M97 engine has the improved IMS, you will need to check your engine number.
if the engine number is 68509790 and below, unfortunately it still has the smaller removable IMS bearing.
if the engine number is 68509791 and above, it will have the new large single row IMS. The IMS cover also has the 22mm nut.";


In my research, i am finding that the rate of failure between the smaller, replaceable bearing is the same as the "updated" larger, non-replaceable bearing. So i guess thats a "plus/positive" if you think about the big picture. LOL