Originally Posted by Richard Wooldridge

Question: Did the repair tech flush the system and replace the drier?

If the old compressor was in the process of failing and/or failed, those things need to have been done to assure a successful repair. Otherwise, the expansion valve would surely get plugged up with contaminants from the old compressor. So, you should make sure that the system was properly serviced! A new compressor should make no noise when properly replaced. Compressors do make an intermittent load on the drive belt, which can cause a loose belt to vibrate, so the belt tensioner is a distinct possibility, as the motor mounts would be if the vibration occurs at idle.