Tempreture problem

[Blackbriar]

I have just got a vento 1.9 td and have 1 problem with it. The temp guage on the dash doesn't seem to work very often and when it does it never goes above the 1/4 mark. I've done about 500+ miles since ive had it and the gauge has never moved more the 1/4 way and it's not overheated??

[kite]

Could be a number of things...Coolant temp. sensor broken, thermostat stuck open or gauge not working.
The coolant temp. sensor is cheap, change that first

[Blackbriar]

Thanks for the advice :)
I changed the sensor first (didn't make a difference) and have now just changed the thermostat and yippee! gauge now stays about half way all the time :)

BUT :( now the fan kicks in after about 5 mins of driving and stays on. I drove 60ish mile tonight through heavy rush hour traffic and some fast motorway miles and the fan was on all the time. the temp gauge never went above or below haf way point. is that normal or a dodgy fan switch or pump?