[RKC]

I don't know how rare it is, all I know is that it happened to my 2007 Targa 4S at about 18,000 miles. The dealer fixed it under warranty. Interestingly, they took all sorts of photos and talked to some higher ups and rebuilt the engine, rather than replace it. Total bill for the rebuild was around $11,800 as I recall. Not sure if that reflects what I would have had to pay if the car were out of warranty.

Porsche finally gave up on the IMS in 2009 997.2's, I think.

The engine failed with no warning (sort of - see below) - a sound from the back like a belt being mangled, warning/charging lights flashing, and power steering failure - luckily just a few blocks from home. Flatbed to the dealer (nearby, but the drive belt runs the water pump).

After talking with the techs, they asked it there had been a more lumpy idle or out of balance sensation at idle. I think perhaps there was, because I remember thinking something felt a little weird at startup in the days before, but it was subtle and wasn't severe enough to cause worry.