2004 BMW Z4 Q&A
2004 BMW Z4 Question: Overheating 2004 Z4 60,000 miles. fans all work, coolant is full.
Took it to the dealer (rip off). They tested everything and replaced the sensor sending unit. Flushed the cooling system, bled out the air...problem still exists. Any ideas on what could be causing this? I don't want to just start replacing parts randomly. Mechanic said the Z4 runs hot but I don't buy that. Temp. gauge gets up to 3/4 mark. I don't want to blow a head gasket. I think the temp gauge needle should remain near the vertical position not vacillate up and down. Also A/C shuts off when the temp. goes up. Mechanic also said the gauge is not actually a gauge but instead a buffered switch. Any insight on this would be greatly appreciated. Car is in perfect shape and has been well maintained. - 04Z4 San Antonio
If it has a problem and that needs to be determined first. These cars assuming its a 3.0 liter engine have had issues with thermostat and water pump that becomes weak. Cooling fans are computer controlled and can cause problems also. I think it needs to be determined if its running too hot or not first. Its a very involved cooling system that needs to be checked by a good qulified technician. - milesauto