pmlzl - please post here how long your water pump lasted. I'd for everyone to keep the community updated with how long their pumps are lasting.
how long did your first water pump last?
http://www.1addicts.com/forums/showt...4#post12932454
also check out these kits...
[B]e8x e9x electric water pump
$439...
http://www.turnermotorsport.com/p-27...53-engine.aspx
And here is there e8x e9x electric water pump and thermostat kit
$571...
http://www.turnermotorsport.com/p-16...-e60-535i.aspx
ALL bmw cooling "kits"...
http://www.turnermotorsport.com/c-10...ter-pumps.aspx
As to when one should replace their waterpump... (taken from Turner's website e8x pumps)...
...
How to avoid a water pump failure in the future? Replacing the water pump as part of a regular interval schedule will ensure you always have a functioning pump in place. Since this technology is relatively new for BMW, therefore the lifecycle of the pump isn't yet known, we have been recommending replacement every 80-100k miles. This package of OE/OEM parts covers everything with Original BMW coolant offered to finish off the job. A proper bleeding procedure must be followed with the new electric pump.
Tischer (
getbmwparts.com) and Dan at United BMW (
unitedbmwonline.com) both offer factory water pump and thermostat kits for similar money. You will need BMW coolant and labor should be a few hours work.