TD5 overheating

Hi, in need of some advice, i have auto td5, alls well until i turn heater on and then temp gauge starts to climb and i can hear clonking noise from glovebox area /enginebay sounds like valve closing quickly, any ideas , i would like some heating

what mileage has it done?

prob the head gasket

earlier ones can crack the heads

Its done 150000 so high but not losing any water and oil still looks good, if i turn heater off temperature gauge goes back down ive got air con would it be anything to do with that ?

Did u try to bleed the system lately?

yeah system had recent anti freeze change ive only had it a month and dont use every day done 150 mile round trip at weekend but didnt have heating on all was fine, yet done ten miles with heating on gauge went into red turned off and gauge returned to normal

19BRI66 said:

yeah system had recent anti freeze change ive only had it a month and dont use every day done 150 mile round trip at weekend but didnt have heating on all was fine, yet done ten miles with heating on gauge went into red turned off and gauge returned to normal

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That's a strange one ..... to make sure about the source of this eeriness try something.....turn the heating on when the engine is still cold(after u started it and didnt have time to warm up)......if the gauge will go on red then is some eldritch electrical strangeness as the temp gauge or the sensor is getting a false feed), or even the ECU is making tricks

Thanks will give that a go