I have a coolant leak on my 04 545i, big surprise. I've replaced top and bottom hoses, expansion tank and thermostat with O-ring. However now I think something busted on my water pump housing, Ive attached the pic. Anyone know what this part is, if its separate from the water pump and what can be done? Thanks for any help or insight!


Pic can be viewed here
http://imgur.com/JAniNFW

 

I was wrong...
As healthservices stated below, it looks like part of thermostat.

 

looks like part of your electronic thermostat

 

Thanks guys, I agree with your thoughts. Found the break away diagram here. Anyway thanks again!

http://www.circlebmwparts.com/cgi/pa...rds&nh=29&mh=1