[A930Rocket]

I’ve replaced every piece of the cooling system except the radiator and fan about a year and a half ago. I’m not noticed any problems, because of the factory gauge and it safe buffer zone.

The factory temperature sensor is at the back of the engine, near the head/block. No way to easily access without pulling the intake etc.

I’ve read about the 1.2 bar cap and that is a good idea. With all of the plastic cooling components i.e. radiator end caps and expansion tank ready to fail.

BMW really over engineered it, as there is no relay. There is constant 12v power to the fan and the DME sends a signal to the fan controller to turn the fan on. It’s also based on the AC being on, vehicle speed, water temperature, etc. Based on all the inputs, it varies the fan speed from low to high.

I’ve read that if the fan is not working properly, it will not allow the AC to work. Driving yesterday and 90° ambient temperature, my AC was blowing 60°. Later on it started blowing out 45°.

I’m going to check the AC system today to make sure it’s fully charged and hot wire the old fan to work until the new one comes. I want to see what that does with cooling temperatures.