1993 300se timing
I recently had a shop attempt to replace the head gasket on my 1993 300se. The car ran perfect going in and is now undriveable . They say the timing advance won't stay in place and it needs to be replaced (the gear). Another shop said it was the harness insulation gone bad from the head removal and that that needs to be replaced first. The car is making a rattling sound when you accelerate, along with no power. After a head gasket replacement, what did they most likely damage to create this mess- the gear, the harness, the computer, all of the above? It is a 3.2l 6cyl. The rattling sound is not preignition, it sounds like a gear, and only on acceleration. The car also idles horribly.
Is there also a timing chain tension issue? I would greatly appreciate any assistance in this mess. Thanks