Hello, I have a 2000 Grand Prix with the 3.1 in it. The temp gauge isn't working and the cooling fans will not come on. I was told that there is more then one sensor and I'm having trouble with the location. There is only one I see which is right at the side of the thermostat housing and is a three probe plug in.

I was always under the conclusion that it only had one or two wires. Maybe it is different on these newer models?

Answer: Yes, the 3.1L V6 has only 1 sensor. This has 3 wires because it is used by the PCM for fan to prevent overheating, and the dash cluster for temp. gauge. Dark green wire is for the gauge, the other 2 are for the PCM. If the sensor is replaced and these gauge and fans still do not work, i would suspect a wiring problem.

Temperature Gauge Went Into Red

1999 Pontiac Grand Prix SE.
Engine Size : 3.1
Question: On the way to college, my temp gauge flew up into the red. 2 minutes later I parked the car, opened the hood. I heard hissing and steam/smoke coming from somewhere just under the belts. I turned it off and got it towed when the day is done. With a light I could see that maybe the leak is coming from behind one of the spinning things, or one of them that does not spin. Could this be water pump? I'm thinking steam/smoke would be my water pump or water pump seal went. Any help would be appreciated.

Answer: Yes, this does sound like the water pump. The item you are describing is the water pump pulley. It is the pulley under the black plastic belt cover on the front of the engine toward the radiator Many times the belt diagram is on that piece of plastic.