pump noise from passenger side rear ? ? ?

[E70x5]

So i start the x5 this morning and get this wierd noise from the rear of the truck. It sounds like its the self-leveling pump going in and out. Usually its on for about 20 seconds and then its gone. But with the sound it sounds like the pump is not able finish pumping and its struggling to pump. The noise goes away if I put it in neutral, but gets worse if i put it in reverse. After driving around for a while it may go away, but sometimes when I'm stopped at a light i can hear it trying to pump again.

[Craig]

Do you have a diesel? I hear the pump running on my diesel after I shut off the car in my garage. I've never figured out what it is. Maybe the urea pump? I've never heard it in traffic, only when I shut off the car.

Craig

[E70x5]

2009 3.0

[rh71]

is this what you guys are talking about?

http://www.xoutpost.com/bmw-sav-foru...fan-turns.html

[E70x5]

The noise generally occurs when I'm stopped at a light and it sounds and feels like the pump is struggling, it also goes away if I slide it into neutral and is louder when I'm in reverse. It's a mix of buzzing and vibrating (kinda like when u first turn on the AC). I think it may have something to do with the self leveling susp. I park on a hill sideways on a slanted angle so the right side is always a little high than the left and I'm thinking the sensor gets confused whether and can not determine if the X5 is level because of the downhill slant I park on. Hopefully this is the problem, I will try to lark on a flat surface tonight. Thanks for the input guys !