I have a 1999 Chrysler Cirrus with an automatic transmission that my son was
Driving when it started shaking, rattling & vibrating before it stalled. He had the
Car towed as it was making such a racket that he did not want to risk damaging
The engine. I am open to suggestions as to where to get started in troubleshooting this car.

. Check for codes.

. Check fluid levels and condition of the lubricants.

. Check for overheating.

. Check the catalytic converter (blockage).

It's hard to diagnose this situation from afar. It could easily be some sort of engine bearing failure, due to the oil not being changed frequently enough. I really hesitate to say. Did your son drive it hard and not properly maintain it? Was it overheating, which warped the aluminum head, and blew the head gasket?