Well apparently I had a valve spring failure on my '08 M5 with 87k. Exhaust valve spring failed caused the valve to hit the piston, bend and a piece of the valve broke off and welded itself between the intake valve and valve seat. Pictures coming soon. Now we'll see how my exclusionary warranty handles this repair. Thing that sux the most is I was just driving home from work when it went into limp home mode, luckily my Indy is on the way home. I have the USAA (underwritten by Asurion) exclusionary warranty, on my second renewal. The first renewal they replaced my SMG with no issues so I'm hoping for the best.