Just the other day i noticed that my car is vibrating like crazy at idle up until 2000 rpms. When i start my car everyrthing inside the car vibates bad. My windows sound like they are going to rattle out and every piece of plastic on the inside does the same. My rack and pinion got replaced last week because my other cracked. Could the new rack and pinion be causing this? Also, my mechanic told me one of my motor mounts is broken. Could this cause severe vibration at idle? One last thing, it seems to get worse when i turn on the ac. I know the vibration is coming from the front of the car somewhere because i dont have gears or anything. Any help is appreciated. 
