2002 A6 Quattro 85,000 miles

Hey Guys, I'm writing in desperation and hoping you can help. We've been dealing with this issue for weeks. Back in early November we took the car in for a CEL. The dealer replaced an LDP pump. Ever since, the car has vibrated while stopped in drive. It idles smooth and does not vibrate while in park or neutral. It does not vibrate while car is motion.

In the 2 times that we've taken it back, they have replaced a motor mount and say they've done a smoke test. The problem persists. This vibration did not occur prior to that pump replacement. From all that I've read, this points towards a vacuum leak. I believe these guys are tired of dealing with us and don't want to do the work of finding the leak.

Any and all responses welcomed and appreciated.

John