thermostat/temp gauge

[123bernadett]

My temp gauge does not move however far i drive.Theres plenty of water in it so i believe thermostat is at fault.What i wish to know is will it b ok to drive c150 miles as it is and how much roughly to replace? Car is escort auto ghia 1600 e reg Thanks

[chasbo]

IMO the fault may lie in the temperature sender unit. Usually a screw in unit, near to the thermostat housing. Cheap to replace. If the thermostat was jammed open, there would still be a reading at the gauge. I would think there was no problem in driving 150 miles, but put a gallon container of water in the boot!!