2009 BMW 335i Sedan [0.00] Make sure that the fan is not obstructed. If not and the fan is getting correct voltage and a signal then the fan motor is probably shot. I've consulted the Bentley manual and it doesn't indicate recoding is necessary if the fan is replaced. If it does, this might be the issue as well. 2When the ignition is on, set the heater to the highest temp (84 deg.) and set the fan on low. 3.Hold down the accelerator pedal for 10 seconds then release. This activates the water pump and it will cycle for about 12 minutes to vent all the trapped air into the coolant reservoir (it sounds like a min washing machine). A technician will diagnose your BMW 320i heater using the symptoms you report as a starting point. Because your BMW 320i heater is a complex mechanism that uses an electric fan to blow air through a heater core that is heated by the engine coolant, the problem could be electrical, mechanical, coolant-related, or a combination of these systems. You may need a torch. With a long flat object (like a screwdriver) try to rotate the fan (another reason why the ignition need to be switched off. If it wont move then try something larger like a file. This will give you a larger surface area to apply pressure to the vanes of the fan without risking damage to the fan. If the fan does run, then the water pump is most likely the culprit. Rule #1 with BMWs: The very second you see any evidence of an overheat warning, you pull off the side of the road, shut off the engine, and call a flatbed. No delays. No exceptions, because if you think maintaining a BMW is expensive, get a quote for an engine rebuild. 381 posts · Joined 2011. #1 · Dec 15, 2017. When car is warmed up (engine temp over 95°C ) and both heater controls set to 28°, heat is only coming out on one side of the car - drivers side. This for the foot well, face vents and windscreen vents. Played around with the re-circulation controls, fan, temp settings but makes no difference. 08 335Ci. 904 posts · Joined 2011. #2 · Apr 12, 2018. The box and glove box both have to come out. The e box because the fan snaps into the hole and the glove box so you can get to it. Once the fan is loose it slides out to the left. Not the most fun job, Newark electrical was charging $80 for the fan. Just solider on the old connector. A technician will diagnose your BMW 335i heater using the symptoms you report as a starting point. Because your BMW 335i heater is a complex mechanism that uses an electric fan to blow air through a heater core that is heated by the engine coolant, the problem could be electrical, mechanical, coolant-related, or a combination of these systems. The only thing that changes the temperature at vent level seems to be outside temperature. This morning it was 30F outside, driver vent blew some warm air but passenger vent blew cold. This afternoon while it was 54F out both blew warm while on interstate. Last week when it was 20F both blew cold. In this article, I'll go over the steps involved with replacing the radiator on BMW E90 models. Be sure to work with a cool engine and confirm the cooling system lacks pressure before opening cooling system. Drain cooling system. See our tech article on cooling system draining and filling. Remove electric cooling fan. ctaG.