a8lchi

Had this noise this AM, in the video. Car shut off when driving, now turns over but no start. No smoke, no leaking fluids.

MP4.2+6.0

Need a scan with VCDS. Anything else is guessing and way too hard to narrow down.

the_duke

When was the timing belt last changed? My money is on failed timing belt. If you don't have VCDS I would pull the timing covers and have a peek.

a8lchi

Not sure. You think the timing belt blew? Seemed intact when I looked, but it may not be there anymore. Not sure what I was looking for.

Jack88

Failed tensioner or water pump took out the timing belt, maybe? That was a very bad noise for it to make, I can't believe you drove it making that noise! If a car's engine is making strange noises you can not identify, do not drive it or run it. A mechanic might run it for just long enough to hear the noise if he doesn't see anything obvious, but no more than that. If you did take out the timing belt, the car is essentially totaled.

Mister Bally

Your "not sure" answer speaks volumes. It seems that you may have bought the car used and have no idea about the service history of the car. If so, good luck with it.

Remove one of the two covers (secured with two Torx head screws) at the front top of the engine beneath the "4.2 V8" decorative cover and post a pic of what's under there and one of us will offer another guess.

No pouring in a can of STP motor Oil Treatment to fix this issue I'm afraid......

Who knows, May not be timing belt related at all. That would be a good thing.