I have a 2004 A8L. When pulling in my driveway this evening I noticed a clicking noise coming from the front of the car. It sounded like it was coming from behind the wheel on the passenger side, but upon further investigation I can hear it from both sides, almost like it's coming from the center of the car between the front wheels. It is just more prominent on the passenger side. And I can't hear it much from under the hood, just behind the wheels. Sometimes it clicks faster and sometimes it clicks slower, but it is constant clicking until I turn the car off. It kind of sounds like something is trying to adjust itself. Any ideas what this could be?

 

Just a wild guess, because of the location, but have never heard of this specific symptom ( but failures do happen, though):

Motor mounts are 2 stage electro-hydraulic....soft at idle and creep speed and firmer above 1100 rpms. If there was a short, bad connection or signal problem, the solenoid that controls the hydraulic valve could theoretically make a clicking noise on one or both mounts(?)

 

The next morning the noise just went away, and hasn't returned. I'm not sure if I should be concerned or happy.

 

Understood....hard to find a potential problem if it won't malfunction.

Who knows, maybe the noise is not even part of the car

 

Well it wouldn't be the first time I've heard noises in my head