I recently bought this car and just had a cooling problem.It overheated and blew the overflow hose from the thermostat housing.I've replaced this, and my heating problem was due to a faulty thermostat which I've replaced. Now, my heat gauge is not functioning properly. The car will warm up properly, but as soon as I drive about 200 yards, the heat gauge goes right to the top.The engine, however,is not overheating.I've ordered a new sensor, but I'd like to know for sure this is the problem. Thanks. Pat.

 

Pat:
If you are SURE the engine is not overheating, then likely it is the sensor rathe than wiring or the ecu. I don't have a chart of resistance vs temperature, but you can compare your new one to the old one. To see if ther sensor and circuit is responding, remove sensor. reconnect signal wire. Boil water, put in cup and immerse business end of sensor in water. It should read at the high side of normal to mid between normal and hot.

 

Thanks for the info. When I shut the engine off after it went into the red, I could put my hand on the valve cover and the left hand rad hose no problem.