My 2007 328i (E91) waterpump gave it up last week at 5.5 years and ~90,000 miles.
I had noticed the coolant was low a week or two earlier and added maybe 8 - 16 ounces to the reservoir.
Had the yellow warning lamp come on and then the red lamp about 10 seconds later. Pulled over immediately and had the car towed. Didn't want to take any chances.
Replaced the pump and thermostat myself over the weekend. Took about 8 hours with the car on jack stands.
My previous bmw, an e36 lost its water pump at 60,000 miles.
Last edited by nilknarf; 02-12-2013 at 10:46 AM.