I just wanted to share some findings on my 2001 Monte SS with the 3800 series motor. I have had the same problem that some of you have had with the temperature gauge not working and I set out to replace my temp sensor. Before I removed the sensor to go purchase a new one, I thought I would do a continuity test on the sensor first. I unplugged the cable coming from the sensor at the point where it plugs into the wiring harness just above the front exhaust manifold and checked the resistance for the senor at that point. I got a 95000 ohm reading which is very high and usually means that the element is almost open. This would warrent changing the sensor. However, I noticed that the lead to the sensor was also plugged into the sensor itself. I unplugged the sensor lead from the sensor and did a continuity check of the leads and they checked fine. I could not get my meter leads to the prongs on the sensor so I just plugged the lead back into the sensor to see if reseating the plug would make any difference. Well, it did. My new reading was 1095 ohms. This is still a little more than it should be but maybe enough to make a difference. I plugged it back in to try it and started the car. I noticed the fan on the radiator came on again so I shut the car off and disconnected the positive cable from the battery and grounded it to reset the computer. Reattached the battery cable and started the car. My temp gauge is working now. I know some of you will say that it will not last but I am going to watch it to see how long it works. Some of you have said to replace the sensor and that will fix it. Well, yes you are right. But, in a sense you are actually reseating the sensor lead to a new sensor. For some of you that are wondering where the sensor is, it is located just below the thermostat housing. The thermostat housing is on the motor where the top radiator hose mounts to the motor. When standing in from of the car look to your right side of the motor(driver side) about two inches below the thermostat. There is a lead about eight inches long plugged into the sensor that plugs into the wiring harness above the exhaust manifold. Unplug both ends of the lead and it would be a good idea to spray some contact cleaner into the plugs and then reattach them to their correct places. I hope this works for everybody. I run into these sort of problems every day at work. So, I thought I would apply the same troubleshooting technique to this problem. Good Luck.

 

I think most of us found it to be the thermostat to be the problem. It was opening way too soon. We just replaced the temp sensor since they were both pretty cheap and in the same spot.

 

I think I tend to agree with you on that one. I have continued to do some research on this and found something interesting at Ask.com .There was a guy that posted some codes that mentioned three possibilities. 1. The coolant level sensor 2. The ECT(engine coolant temp) sensor 3. The thermostat. The thermostat opening early or just staying open would make sense out of the problems that we see with the temp gauge not working. Most of us have said that the temp gauge will work during warmer weather. Well, your engine runs warmer in warm weather and therefore satifies the computer as to the proper run temp of the motor. In the colder months your engine temp may not be able to get to normal range and the computer senses a problem. Shutting off the temp gauge may be the sign that the computer gives you that something is wrong. Also, if the computer does not trust what the sensor is telling it, then the computer faults and runs the fan the whole time to protect from overheating. I am going to change just the thermostat and see if that takes care of the problem. I'll keep you posted.

 

in my 04 ls my temp gauge never reaches the middle line it stops right below it and it has never went any higher or went any lower would dat be the result of any of these problems?

 

Sounds like it might go. Mine did the same thing before the temperature gauge died. It'll go up before the middle line on the gauge...then just die.

It might be going.