My sad story is as follows:
03 plate 147 JTD 115
Bought in summer 2008
Faultless for a year temp sitting at 90 all the time, any load, any speed etc
Last summer I left it running in the sun for 20 mins or so and when I got back in the temp had climbed to 100-110
Driving home that night it lost its coolant and the temp shot up to 130 so I limped home, filled it with radweld and all OKish.
Since then the car has run hot, but this can be resolved by turning the heater dial to "demist"
The timing belt and water pump were changed last month, but the problem is still there.
I'll check the thermostat as per the sticky, but my problem seems to be one of too much heat rather than not enough.
Is there a valve that should open to cool the engine but with me is sticking closed?
Let me know what other info would be useful