I have a new thermostat in my BMW Z3 but it stays normal when i am driving on the highway. When i go into town the car heats up and then goes back to normal and then heats up again. What is my problem?
heating problem on 1997 BMW Z3
When they added new coolant you need to purge the system of air.You can google the procedure like on the Peligan Parts web site. I had the same problem when the previous owner change coolant and did not purge the system. I have a 4 cylinder some ther are a little different steps. Drove me crasy at first but not overheating now air in radiator gave cooling fan a false reading and would not come on.
I would make sure that your cooling fan(s) work correctly and that your radiator flows properly. Are you driving with the A/C on? I ask this because there is a dedicated electric cooling fan for the A/C system when ever it is used and it should come on as soon as the A/C is engaged. If this is not working correctly your car will run hot when it isn't on the highway.