Tapping noise (540i 2003) video inside
 

http://www.youtube.com/watch?v=82I_drq48Iw

Any idea what could be causing that tapping noise towards the back? my car drives/idles fine, no leaks. but it's got me worried

Also towards the end of the video you can hear a tick, it's like right below the coolant hose and right above the alternator, it's not always there (comes and goes) but I can feel the little black thing (not sure what it's called, it's above the alternator on the driver side front of the engine) "vibrate" in rhythm with the ticking?

edit:red arrow pointing the to the thing I can feel vibrating with the tick.
http://img.photobucket.com/albums/v7.../540Engine.jpg