ford focus temp gauge

[flossy34]

my cars temp gauge was like a swingometer so took it to the garage to be fixed. a new thermostat was put on but still not working properly. took it back again,the garage had it on a machine to find any faults with the car but was told they could find none. said it could be the new thermostat just settling down. temp gauge still doing the same thing but only now and then,fan seems to be running more than it use to. any ideas anyone?

[philandlil]

it might be the temperature sensor its usually found on the thermostat housing or water pipe between th engine and radiator. Changing the thermostat itself would have no effect on th guage as it only controls engine water temperature not the guage in the car. As for the fan running more often there may be an air lock in the cooling system if they have disturbed the thermostat which will cause the engine to overheat