I've searched the forums but couldn't find anything close, has anyone experienced this? -- I usually don't let the car idle for very long but in the few instances where the transmission has been in Park while I've had the engine running for about 3-4 minutes, I begin to hear a tapping sound as if someone is hitting the boot with their hand, no rhythmic pattern just random tapping.

R56, outside temperature can vary, rain or shine doesn't matter. The tapping stops when I shift into gear. Then after driving and I shift into Park, no tapping sound unless I've let the engine idle for another 3 minutes, then it starts again.

 

I've heard this too, but only when I'm in neutral (have a 6MT) and just letting the car idle for a few minutes. It'll start after about 3-5 minutes and will happen randomly at maybe 45 second intervals until I move the car. Very weird, but I wasn't overly worried about it since it's pretty rare i sit with the car on and in neutral.

 

Hmm... transfer pump in the gas tank perhaps?

 

The correct search term is THUMPING noise.

 

Yep, I got it too. Dealer "can't do anything" about it.

 

It's a Boot Monkey...wanting to be let out!!

 

Well, we have the same problem in our 2008 Mini, but in our case it happens if we continue to sit in the car for several minutes after we turn off the engine, which doesn't happen very often. We haven't attempted to have it fixed since the situation in which it occurs happens so seldom, but it sure is mysterious as to what is causing it.