My 320ML had a pulley replaced at about 77k when the engine was making a clacketty noise. Is that the same as a harmonic balancer. Also, the car at idle seems to have a vibration, but normal on acceleration. So are you guys saying that if the this harmonic balancer fail, can it cause catatrophic damageto the engine? I recently had a 450sl that a ramp broke and cause valve damage. Thanks in advance.

John