Is the 2001 engine considered an interference or a non-interference engine, if a timing chain issue comes up. A newly rebuilt engine was put in my son's '01 Dakota. It would turn over but would not start, after several attempts. Every thing was checked and rechecked. Finally pulled the front cover off exposing the timing set-up and found the problem. The crank gear spins on the crankshaft. Don't know if there's valve damage or not at this point. Don't know whether to change out the gear and keyway or pull the motor and ship it back to the builder under warranty at this point...