Originally Posted by BMWs4ever
Most water pumps fail around 100K. I also own a Passat and I have to change the timming belt around 100K since it is a rubber belt. When I change the timming belt I also change the water pump since it is a huge pain in the ass if the water pump were to fail 10-30K later ( you have to take half the car apart for a timming belt or water pump) and I highly doubt it would make it to 200K.
Bottom line I will change my water pump on my BMW at 100K if it had not already failed because you are asking to get towed if you don't so why gamble and get stuck somewhere in the middle of no where usually at the worst possible place. I consider water pump replacements at 100K part of the cost of owning a high mileage car.
I did the same thing for my wife's Honda Odyssey - changed the thermostat at the same time as the timing belt.
Although if I keep my 328xi until 100K, I am looking at a pretty hefty bill to replace the water pump, thermostat, trans and differential fluids.