cylinder head temperature sensor

Yes the sensor is under the intake. It is item B135. No you cannot re-locate it somewhere else and have it actually work properly.

Thanks for the help! I cannot seem to find any other v8 LS's that have had this problem. which makes me wonder if I am on the right track. I know I am I am just grasping at straws. Thanks again!

What is the issue?

the car overheats. or I should say that the temperature gauge rises. sometimes you can put the heat on and it goes down, but there have been a few times that was not working so I played with all the settings, A/C, vent controls, and it came down. about 25% to 30% of the time the gauge just falls to the normal place, falls like the needle bounces when it comes to rest. You can turn the car off and start it up again and it will be normal again.

Does it actually get hot or is it just the gauge that says it's hot? It sounds like a bad connection to the sensor or a bad sensor. Any check engine light?

Hi! I have same problem with overheat on LS V8 2000. Any check engine dont light. New thermostat is not help. Its make me crazy - Im really dont know what can I do with this. Please, help me to.
"Does it actually get hot or is it just the gauge that says it's hot?" - I dont know. How I can check it?

You need to use a mechanical gauge or an IR thermometer to verify the actual temperature. Say the dash gauge reads 240 degrees, but when you read a mechanical gauge in the top radiator hose it reads 200. Current engines run that hot most of the time. So the gauge is reading hot, but the coolant actually isn't hot.
The sender could be bad or it could be the stepper motor in the gauge itself.

Or the test gauge could read the same 240 as the dash gauge. That may still not be "hot". Does it boil over or lose coolant?

Thanks for you answer, but I was solve the problem today :)
"Does it boil over or lose coolant?" - no.
How problem solved: I just touched and a little shake (and turned it on some degree around axis) "HYDRAULIC FAN PUMP ACTUATOR" and spray WD-40 on surface. And cooler fan now work properly, with all speed range. How I understand, problem was in fan speed - it was too low all time. May be dirt or something some.

I had bought a car and everything was normal, on a trip the temp gauge went up. checked everything and finally found that there was a build up of leaves and pine needles between the a/c condensor and radiator from the car sitting under a tree, it made it so the air could not go through the radiator, This is something you might want to check. ,