Mk4 20V turbo running hot

[Kelvin1977]

Ok wonder if you lot can help I have a 2002 20V Turbo and I am getting some strange things happening. 95% of the time goes up too 90 deg and sits perfect, but every so often it rises to 100/110 but no higher. Then drops back to 90? I would have guessed at water pump but it was done less than 5k ago with the cambelt and also thermostat and housing. Could it be a temp sensor or dodgy fan switch 

[jamie16v]

any particular pattern to this happening?. sitting in traffic, on the move etc?.

[Kelvin1977]

No completely random only thing I think is does it after its been at tick over for 5 mins but does not rise when I am sitting but about 10 mins after I have got going again.

[jamie16v]

leave it run on idle for a while and monitor it, see if the fan kicks in etc.. scan for codes too, it might show up a code for the coolant temp sensor, implausible signal?.

[navmk4gti]

Temp sensor my vote

[Kelvin1977]

Done that mate goes up too 90 and holds other times goes up to either 100 or 110 but never any higher. Have scanned no codes 

[gazareth]

the fan usually comes on just over 100c. rev it to 3000rpm in neutral until gauge goes right up then just before it hits the red zone it should fall back down. then you know your fan is coming on.

[Kelvin1977]

Ok will try put fan is working as have heard it when I get out of car 

[gazareth]

are you getting hot air through the heater blower?

[Kelvin1977]

Yes mate no probs there and no other probs