One possible issue is that the MPi Minis came with a thermostatic switch harness that was too short. The stress breaks the wires and causes it to run all the time. A fix (longer harness) was released but it seems many MPi cars never got the fix.

The part number for the extended switch harness is YMQ105690. Our host sells it here: Coolant Fan Harness Modification Rover Tech Bullet (minimania.com)


DLY

What's the ambient temperature at the moment ?
The fan will run quite a lot when stationary as the radiator is on the small side and needs a decent airflow to cool, and you have no prior working knowledge of this particular car.

I'd suggest going back to basics to start with and thouroughly flushing the cooling sytem.   When you refill it, DON'T use the standard off-the-shelf 50/50 Prestone style "coolant" - clean water with 10% antifreeze and a bit of water wetter will improve your heat transfer enormously.

Alex, thanks for the response. To answer your questions I'm in north Texas, I took possession of the Mini a week ago. It was shipped to Spain in 2005 from Germany.

Is this a new thing, or has it always done it - you don't say how long you've had the car or where you are.

As a German market model, it's only been US compliant for a year or so (this place is predominantly North American).

I have a 1998 Mk7 Mini Monza and the radiator fan runs constantly when I start the engine.  I've unplugged the thermostat switch so that's not causing the problem. Anyone know what's at play here?