hopefully someone can help me with this problem i have had for over a year, so the car has just been sitting and i havnt time to mess with it. I have a 96 328i convertible and i cant get the cooling system right. one day i parked in my driveway and left the car running, ran in the house for 5 minutes, came back out and the car was about to die with smoke pouring out and coolant all over the ground. turns out the expansion tank where you put the coolant in cracked. so i bought a new one, changed the thermostat, and the car is still over heating. i dont think there is any coolant flowing. i have replaced the water pump twice in the last 5 years...so i doubt that its bad. i could be wrong though. If i blow into the expansion tank, coolant will flow for a few seconds.