I have a 2000 LS with 3.9L V8 w/ 100l+ miles. I was driving home one night, stopped and turned the car off at a rest stop for 10 minuted and could not restart the car. To make a long story short, it turns out that the chain guide that sits over the cam sprocket broke and wedged itself in the chain and the chain broke. My question is, can the piston hit the exaust value if the exaust cam is not turning? The car was not running at high RPM when this happened. In fact the car was idling before I turned it off for 2-3 minutes without any problems or unusual noises.