my heater works as expected under normal driving conditions, however, at idle i get only cool/cold air from both floor and dash. all settings are set properly for max heat. if i increase idle speed to about 2000 rpm, warm air then comes out all outlets. i don't know what would cause this - thermostat, water pump, micro-filters? anyone ever have this problem? any suggestions? Tom, Thanks again for the radio fix. My thermostat was just replaced for a similar problem.In my car the temp gauge was all over the place. They also found a leak in the radiator. Expensive repair but I have an extended warranty that picked it all up. I understand the early E39 cars are showing some cooling problems now. Radiators,thermostats and water pumps. Most of these cars have 50K+ and all of the Bimmers I have owned (6)have been similar at this point. The price we pay for these great cars. My neighbor brags about the 100K + cost free miles in his Camray. I drove a new one recently, I would rather walk. What a BORE. Barry thanks, Tom '97 528iA BMWCCA