A little background first, my 2004 Civic LX didn't want to start one day, just heard a click. Took it to the dealer to get it checked out and they tell me the starter is failing and f.y.i one of your engine mounts is broken. So i ask how much for parts and labor and they give me a $700 something figure that kinda shocked me so i said i would wait. Next day I take it to a local mechanic and they said they could do it for like $230 so I went ahead and got it done. They replaced the starter and the bottom engine mount. My car was working fine that afternoon and the next morning but then in the afternoon I noticed when I turned on the car it had a noticeable vibration to it, and when I shifted into Reverse it got worse. Once I shifted into Drive the Vibration died down. The next morning I took it back to the mechanic and they check it out & tell me they can't find anything wrong with it. The conclusion he came to was that my other engine mounts were softer than the new one so its causing more vibration, which gets worse when in Reverse because the Transmission does more work. I'm not really buying that. Soooo anyone got any ideas???

 

Sounds like hooey to me.
A transmission doesn't work harder in reverse, and I doubt the mounts are any softer.
I had a car with a broken motor mount that, when you shifted into reverse, the engine would actually move and cause a vibration, but when you shifted into drive, it jumped back into place and the vibration stopped.