Mini overheating/fan stays on?? how to cure

[bigbenn36]

Hello all, My girlfriends 2001 mini one has developed a strange range of symptoms and I am at a loss as to the cause. The symptoms are:
1.engine fan comes on full blast after approx 15 mins and stays on when engine turned off for about 5 mins
2.interior heaters blow cold even when on full temp (no damp patch near heater matrix)
3.exterior temp display(on pod when rev counter) displays 50 degrees C constantly (currently 15 degrees not 50)
4.engine temp reading halfway (correct??) then shoots up high when car parked up and turned off, also when car ticking over and stationary.
5. car was losing coolant but a leaking upper radiator hose has been repaired and so far no coolant loss after 2 days.
6. before the hose was repaired the car lost power, suggesting it was actually overheating, not just a false temp reading causing the fan to kick in.

Does anyone have any clue where the problem could lie?
also, are the engine and external temp readings related? possibly faulty thermostat causing false readings and fan to kick in needlessly??
There seems to be so many potential causes that I have no idea where to look first. If anyone has had similar problems or has got a clue where to start looking I would really appreciate the help.

Thanks

[The Nun]

Heater blowing cold when on full, is a classic sign the cooling system has not been bled properly and has an air lock, this would also probably mess up coolant sensor readings too.

[bigbenn36]

right, I have filled and bled (as best I know how) the coolant system.
The external temp reading dropped to 17.5 but then rose to 31.5 when I drove it????
the car did not overheat, the fan did not come on and the blowers started to kick out very hot air so bleeding/filling definately had a positive effect.
Just concerned if this is a full or partial fix with the external temp reading still being so far out (my car is reading 13.5).
Is it worth repeating the process to ensure it is fully bled or is there little point and should I start looking elsewhere for the root?

[mab01uk]

The external temp sensor is clipped behind the front bumper lower grille to pick up outside temps and has nothing to do with the engine temperature reading, sounds like it needs a new sensor. They sometimes become un-clipped and get damaged waving around on their cable.

As said air in the cooling system is a common fault on Mini's and careful bleeding is required, more details in link below:
Solving MINI Cooling Problems.......... - Forums

[bigbenn36]

I have just been out for a half hour drive in the car, no overheating and no fan and no coolant loss so it looks like bleeding the coolant system has done the trick. Also the blowers now kick out very hot air.
The external temp reading has gone to 50 again and staying there (yesterday it dropped to 17 when I took it for a drive) so looks like that will need to be replaced as it obviously isnt right.
thanks for the advice