Can a bad harmonic balancer ruin your engine?

Answer 1

A bad balancer can cause failure for more than one reason. First, an unbalanced engine can have severe vibrations set up that will cause material failure in the engine, and it will break internal parts. Second, the balancer can come apart physically outside the engine. If this happens, the loose part can cause damage all over the engine room, and if caught in a belt or pully, jam the crankshaft. I've seen this happen!