What is this engine part on my 540i????????
 

Any one know what this part in the picture is? I just bought the car and the part seems to be clicking (both sound and vibration as if something is rotating and catching inside) Thanks!!http://forums.pelicanparts.com/uploa...1224820250.jpg

That is your water valve that controls heat to the heater core in the cabin.

#6 here:
http://www.realoem.com/bmw/showparts.do?model=NB11&mospid=48804&btnr=64_1360& hg=64&fg=18

It is unlikely that that part is making your noise.

I would start with belts and pulleys.

I first noticed the "clicking" when the ignition was on without the engine running. So I'm guessing that the pump may need to be replaced. Could this possibly cause the engine to overheat?

Thank you very much for the insight, much appreciated.

Ok so its clicking with the engine OFF? That's a different story.

That part is the heater core manifold with valves. From the diagram it appears you have another single valve as well.

If you are sure the clicking is from that part, you can feel it clicking, then it could be the valve is bad. The other option would be an electronics failure.

It wont effect engine temperature but it should effect cabin vent temperature.

I would unplug it to see if the noise stops. If so I would replace the part or take it apart and clean it.