I have a 2009 Mini Cooper Clubman s. It is running around 160° f. It seems to have the fan kick into soon. Stage one at stage two are both working but stage two sometimes starts at about 120°f. I changed the coolant temperature sensor and nothing changed. I didn't have time to test it first. I am of course suspecting the thermostat housing but why is the computer telling the fan to turn on at such a low temperature? Does anyone know if there is a temperature at which the DME heats up to and causes the fans to come on? The following are the temps that I was experiencing.

Ambient temperature:85f
Intake temperature:105-110f
Engine temperature:160-170(max)
DME temperature : 120-125

I wondered about the fan motor resistor. If the fan is running on stage1 due to the air conditioning and the resistor begins to fail would it jump to stage2?

I have course have suspected the thermostat but why would the thermostat determine the time that the fan came on? I was under the impression that it was controlled by the DME. If I am mistaken and the thermostat is in fact failing and the controller is in the thermostat, OR at least takes in consideration of that value to turn the fan on then I guess it might make sense.

​I also have pressure on my overflow canister. I just hoped to get some feedback from some others in the know so that I won't spend more time and money.