Tap/click/thunk under drivers side floor

[sixthgauge]

Hey all, this started today. It's a bit tough to describe, but it feels like a tap/very light clunk under the driver's side floor. It is timed and methodical, kind of like windshield wipers going back and forth. It is present both when the engine is on and off (but battery on of course). I notice it both when I am standing on the brakes and when I am in park. Thanks in advance for any ideas.

[Pelican Parts]

Hello and welcome to the forum! I had a very similar issue - does the car 'hard' shift once in a while as well? If so, it may be your fuel pump - not the mechanical one, but the one with the gas tank. Take a look at the link below to test it.

http://www.pelicanparts.com/BMW/tech...mp_Testing.htm

[jclausen]

Check and see if the straps that hold up the fuel tank are still in place

[MarcoZandrini]

It's obviously something electrically activated. That is, the root cause is something that requires electrical power. Is the clunk occurring continuously when the ignition is in the run position but with the engine off?