Originally Posted by Brad from the OC
Why wait until the waterpump or t stat fails and risk damaging your engine? You got your money's worth out of your pump, replace it now along with the t stat and coolant and not have to dread about overheating suddenly with little to no warning.
Either way you have to buy a new pump and t stat and if you run to failure you might end up with a tow bill also. Some tow trucks have been known to damage your car body and front bumper when it is towed also. So for the price of labor minus a tow bill, you can drive your E90 without worrying about overheating.
It took 1 hour to load the car onto the tow truck and 30 mins to unload it delicately. Huge PITA and a horribly complicated procedure (lowered car with M3 rep bumper and a front tow hook plate which has to be removed etc.)
Get it done at 80K Km.. unless you want to experience what I had to go through.