intermitant temp fault

[Ash1502]

first off my engine fan kicks in alot. its never garanteed when it is going to kick in. it may not kick in during a good trashing but will kick in on my slow drive to work in the mornings, and vice versa.

also, sometimes my engine temp gauge starts to climb towards the red zone. it can do this again whenever it chooses too, sometimes it will do it at high speed during high revs, other times it wont, and then do the same when driving slow.

i have checked my coolant level and than is fine. i rekon my heater control valve is all ok, as my heating system is working 100%. i have not got any coolant leaks in the system.
weirdest thing is though, the other night i was driving on A-roads at about 60mph and it started to increase in temp, i backed off and put the heather on full heat and fan setting 4 and this did releave the excess heat. i dunno why but i did the strangest thing, i booted it right through all the gears till i was going at least 70mph. and the temp gauge dropped right down to where it should be.

my fault is simple, the temp gauge increases intermitantly and the fan kicks in unpredcited also. i want to diagnose the problem, however i am not sure where to start.
please help

 

[mikey s]

I had a similar fault on my old 1.7 that turned out to be an airlock in the system. The temperature climed in various conditions such as slow or motoraway driving. Sometimes when putting the blowers on I even got cold air. However, I did the usual trick running the engine with the water cap off topping it up if required and screwing it back on.