Is your fan kicking in? If not the switch could be goosed.

I will check that out thanx

run it for at least half an hour then open the radiator cap with your teeth.

seriously though take it to the garage ffs

thats yer engine its kinda expensive to replace

The Garage is aware, the problem sorts itself out once i put my heaters on so the idea that the fan is not kicking in makes sense (to me) There is no sign of serious trouble unles you want a square go!!! No really everything works ok but i'm going find out today what is wrong

Nigel is it just a case of replacing the switch? pardon my lack of knowledge on the mechanicals

Yeah just replace the fan switch which will be in the engine bay not far from the radiator. Have you checked the water and oil to make sure there's no residue inside the oil filler cap and water tank? This will be a sign that your head gasket has gone. Could be an expensive job if it has gone.

Keep us informed.

didnt know ttt's had an electric fan.

normally thermo viscous on taxi's

1 run from cold, once warm check that the radiator hoses are hot
if they are then the thermostat is not the problem(it may still be jammed open,but this wouldn't cause overheating just a slow warm up)

2 if you have an electric cooling fan wait until the engine is really hot then the cooling fan should cut in and cool it down if it doesn't suspect either the fan switch or motor,after of course checking the wiring.common fault on all metros because of the lack of decent earthing points.

check the motor buy jumping wires from the battery to the motor if it turns then suspect the switch.

if the above is ok then you can start looking at more serious faults
I:E blocked rad,head gasket etc

if its the head gasket your rad hoses will be pressurized and appear ballooned

if you check oil and water every day then its not likely that your head has been damaged

just go through them all starting with the simplest first.
cooling systems aren't complex

i dont think you are listening to any one dougie