cobalt91

Hi guys, got a question about the temperature gauge. Past couple of days I've noticed on start up my gauge is reading at the mid mark. I'll start. I'll start trouble shooting this weekend, just wanted to get your opinions. There are no codes and its not over heating. Its a 91 with 218 thousand miles.

aomdedude1

This might be incredibly obvious and I'm sure you've checked but how is the coolant level??

My biggest thing to check if I were you is to see if there is anything blocking the radiator. The reason I say this is because if your car overheats at start up or in traffic, than your radiator might be partially blocked up with leaves and crap. Then at highway speeds you'll get enough airflow to cool it down enough to not have the gauge way up there.

After the obvious checks, you need to check your ECT gauge. (the coolant temp sensor for the gauge) There are three gauges. I think the one for the gauge is at the front left top of the engine (looking in the hood at your car) near the passenger side ignition coil. It's the little one. They go bad and should be replaced!! Also check your wiring that connects to the gauge.

If you've checked all that, THEN you can start looking at the gauge itself.

cobalt91

The ccolant level is full. That was the first thing I checked. The wierd thing is this is right on start up.After it warms up the gauge will spike to the top of the gauge and then settle back to the mid mark on the gauge. That makes me want to check the connections to the sending unit to the gauge. ECT sensor is new. Replaced radiator last summer. Water pump is only 10,000 miles old.