non externally replaceable IMS
 

my 99 got a replacement Porsche Factory rebuild engine in 2008 after the original engine cratered with 37,000 miles on it. I have heard the Porsche rebuilt engine in 2008 likely has the non externally replaceable engine. Has anyone heard of the failure rate of these bearings?
James

Any factory replacement engine installed after 2005 would carry the non serviceable bearing. While there is no published data on how frequently they fail, they do fail, but at a low rate; perhaps similar to that of the original factory dual row bearings.

Thanks for sharing! :)

Less than 1%, IF its not taken to the track. On the track the M97 bearings have the highest failure rates, by far.

When Porsche added bearing diameter, and increased surface speed of the bearing, that was great for lower RPM street service, but horrible for sustained high speed operation. I have a directive about this, if you email us.