water pump failure
 

Can hear water pump grinding on cold start up so expect it will have to be changed. This will be the second in under a year and less than 60k miles. car is 2005 330i. questions are why pump failure in the first place, second what are alternatives to OEM replacement. third, does so called "lifetime" coolant contribute to failures?

http://www.stewartcomponents.net/Mer...y_Code=BMWHPWP

thats the mac daddy of them all but you'll pay up front for it. saves you in the long run if you plan on keeping the car a while though

Maybe you're getting really cheap crap pumps? Chinese would explain your situation.

This is in the E39 bestlinks ... lots of good information ... probably applies to the E46 M54 also:
- What brand of waterpump to buy (1)
http://www.bimmerfest.com/forums/att...1&d=1300725016