Hi all, I have had my "02" 330i sport for 1 year now and what a year it's been..anyway, The(water) header tank split 2 weeks ago, the garage put it down to pressure in the system. new tank on, system blead but the temp guage can go from cold(first start up) to hot(half way) in under 1 mile of normal driving i.e going to work. I put a new thermostat on 1 month ago because it was running cold. Before it goes back to the garage i was thinking it could be the water pump has given up :(, Any ideas would be most helpfull. (I've waited for this car for a while now, well worth the wait)