My '06 Aveo thermostat has been replaced AT THE DEALERSHIP 2 times and the problem still remains. The gauge goes up and down a lot,the temp goes hot to warm to cool then back to warm and then to hot and so on. When the air in the car is cold the gauge is on C or close to it,then as the heat gets hotter the gauge slowly goes up to the middle , but then it goes back down and the air gets colder again.
It takes a little while to get warm, but it does not stay constant. When the car goes around a corner,up a hill, etc...... the heat sometimes comes to NORMAL....The thermostat housing was replaced,to the aluminum type,the head gasket was replaced due to a valve job; problem with cooling system started after this was done.
Possible air in system?

 

I would take it back to the dealer and tell them they did not fix the problem. This would be your best bet!

 

i would check the temp sensor for a louse wire connection. my 08 has a temp gage issue also, but i think mine is in the cluster..

good luck

 

Be persistant. Go back TO THE DEALERSHIP

 

Same here, go back to the dealer. You have warranty , dont you?

 

The warranty is still good but the first time I brought it to the dealer the mechanic opened the hood and slowly unscrewed the rad cap, and you could hear pressure being released. He then drove the car, and all was fine for awhile.The mechanoc said all was fine.
The wire is not the problem because the fluctuation in temperature is still there....hot then warm then cold and the gauge seems to woking because as it goes to cold the air in the car gets cold,and vice versa.
Thanks for the response!!!!!!!

 

As far as the dealer is concerned, the car is fixed......even though the problem still occurs.

 

Its not fixed until you accept it

 

What they want you to do is to try and fix the problem yourself (or let someone else fix it). Then afterwards they'll tell you 'sorry, warranty expired because its not fixed by a GM representative. Go straight to jail, do not pass Start and dont collect the 2000 dollars."

Its an old trick.

What was the old thermostat housing? And did they replace it with the right kind of thermostat?
Your thermostat decides when your fan should start working and how hard it should start working. The way I understand it, your thermostat tells it to work TOO soon. In which case, your car never gets the opportunity to warm up properly.

This is what I would do... find a thermometer (your wife might have one of those handy kitchen thermometers to punch in the chicken) . Open the hood and find the hose that goes from the Radiator to the engine. Thats where the thermostat is as well. Let the car run and hold the thermometer against the hose (as close to the engine as possible, without touching the aluminium thermostat cover). the themperature on the thermometer should be the same as the indicator in your car dashboard, (it could be slightly less). If its WAY off...then they used the wrong thermostat. (there are thermostats that measure in degrees celsius instead of fahrenheit. It confuses the On board computer which causes the fan to work too soon. The thermostat says "its a 100 degrees" to the computer. Thermostat would be 100 degrees celsius , but computer would interpret it as 100 degrees fahrenheit. Or vice versa).

Now, this is important , so I'm going to use big letters (and i would like to apologize in advance for that ! )

DO NOT TELL THE DEALER THAT YOU TRIED THIS OR THAT WITH THE CAR!!!!!!BECAUSE IF YOU DO , HE WILL SAY THAT MESSING WITH THE CAR YOURSELF IS CAUSE FOR THE WARRANTY TO STOP IMMEDIATLY !!!!!!!

Someone should put this warning in big red letters, with huge explenation marks and severe underlining.

 

If you are talking about a coolant temp sensor, they are nothing but a variable resister that changes with temperature change.
Your trick with the turkey thermomter will not work. The temp will be way off. the coolant temp sensor reads the temp inside the engine, and before the thermostat. Any hose you find will be outside the engine and after the stat
The thermostat should open a bunch of times before the fan turns on.

Bottom line is, the temp gauge should not be jumping up and down the way it is. It should warm up and stay at a relatively constant temp. Call GM customr service and tell them your story. Tell them about the dealership you are dealing with and how they are not willing to fix the problem that arose after they performed previous work.