1999 montero temperature sensor stopped working

autodr

• 260 Answers
• Posted on Nov 20, 2008

SOURCE: temp gauge cold and then heat turns not so hot

make sure the antifreeze is full. if so, replace thermostat and refill

SOURCE: Temperature gauge shows hot

head gasket does the overflow bootle have bubbles in it when idleing warm if does most likey rear head gasket.

SOURCE: Temp gauge stay on cold.

Switch ig. on, ground the sender unit wire for about 3 seconds see if the temp. gauge moves, if so change sender unit, if not then it is a faulty gauge reader.

SOURCE: Temperature Gauge Always On Cold

As long as your gauge is still moving up, there's no real problem. You have heat coming from the heater. It's only a problem if it's getting too hot. What's going on is that you don't let the vehicle run long enough, and it's so cold outside that the engine stays cold. It raises in temp when your stopped because there's no airflow through the radiator. The thermostat just heats up the engine block, and won't change the reading on the gauge. When this goes bad your car will overheat in just a few miles.

SOURCE: Working on a 1999 Oldsmobile

One guess is there is air in the cooling system. The air pockets will cause temporary overheating (fluctuating guage).

It sounds like a bad head gasket is creating these air pockets.