I have been the subject of overheating resulting in replacement head which also went pop. Now I've replaced the whole engine with a second hand motor said to be good. This engine runs cool with the needle just off the blue. After a few miles the needle climbs to about 10.00 oclock then if I run the engine light the needle drops back to the blue. The heater works fine so hot water is flowing. The radiator hoses are tight to the pinch and reasonably hot. Over a journey the needle slowly rises and falls all the time.

I was wondering if this is O.K. or could the Thermostat be jammed open or could it be missing! Anyone got any advice please.

parranger said:

I have been the subject of overheating resulting in replacement head which also went pop. Now I've replaced the whole engine with a second hand motor said to be good. This engine runs cool with the needle just off the blue. After a few miles the needle climbs to about 10.00 oclock then if I run the engine light the needle drops back to the blue. The heater works fine so hot water is flowing. The radiator hoses are tight to the pinch and reasonably hot. Over a journey the needle slowly rises and falls all the time.

I was wondering if this is O.K. or could the Thermostat be jammed open or could it be missing! Anyone got any advice please.

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Waxstats always fail closed more likely there is no stat in engine. Or fan stuck solid. Or check temp sender.