Drove my 2006 z4 3.0 to work noticed I didn't have any heat . Temp gage straight up. Trip of about 15 minutes. Stopped for about 5 minutes and drove about half a mile when temp gauge shot up. Turned around and parked it for the day. Drove home that evening and same sequence. Never ran hot but about 1 minute each way.no check engine or low coolant warning.
Sounds like you have a overheat issue so I would lean towards a issue with the water pump not spinning fast enough. Have you ever had it replaced?
The blades on these water pumps are plastic and they fail quite readily and sometimes catastrophically. I believe you will find most people on this or any other BMW centric forum will strongly advise you to change your water pump before operating the car again. Prophylactic replacement of the water pump, hoses and the plastic overflow tank are strongly recommended. Read Mike Miller's Old School Maintenance handout for more information. That said, if you choose to operate your car as is, thinking it is a computer fault, then be prepared for a blown head gasket along with various and sundry accompanying maladies. This is just my opinion and I may be wrong (doubtful). (BTW, I replaced the water pump, etc., on my 2003 prophylactically at 65,000 miles.)
Your vehicle uses a electric water pump that has been very problematic for BMW. Yes they can work in and out but is a sign that they are failing. Normally when this starts to happen a fault for coolant pump speed deviation will set but the check engine light will not come on. Another thing to check is to make sure your electric fan is working properly if you turn your a/c on max the fan should turn on this quick way to test it.
Thanks for the replies thanks for the help. Guess the best thing to do is just change thermostat and pump. I'm not one to throw parts at something and hope if fixes the problem .i was just wondering if I should have the computer read. And no I'm not driving it. Thanks again.
