Okay i have an 01 Monte Carlo SS 3800. I have replaced my coolant temperature sensor and thermostat (after discovering that the previous owner took out the old thermostat and didnt replace it). I also replaced my mass air flow sensor. I no longer have any codes coming up but my temperature gauge is always below 140. My car is sluggish after sitting for extended periods of time. I have no idea what else it could be. Any info is greatly appreciated!!!

 

Could be the thermostat stuck open.

 

The thermostat shouldnt be stuck open. i just replaced it yesterday.

 

As unlikely as it is, you may have got a defective one... When you start the car are the hoses hard, thermo closed then does it open as you approach opperating temps?...

Just noticed, welcome to the MCF family...

 

Are you sure you got all the air out of the system after replacing the thermostat? Did you install the correct temperature thermostat? Is it really cold/snow where you're located? Any of these could contribute to low operating temp.

 

I have purchased a defective thermostat on sadly two occasions, so it could very well be that you grabbed a bad one. Also the air in the lines is another possible culprit.

 

Welcome to MCF!
Not to belittle you abilities but, are you sure you put the thermostat in the right way? Also, how is the Heat in the car. Is it blowing warm or hot. Proper bleeding is important. You may have to bleed it several times to get all the trapped air out. Did you do a complete flush or just replace the Thermostat and Temp sensor! You may have a clog in the system. Finally, are you sure the gauge is good? Your system could be fine and the gauge is giving you a false reading. If your heat is good once you've reach N.O.T. your gauge is more than likely bad!

 

I guess i didnt get all the air out. I drove around and i could feel the air in the line(guess thats what it was). but it smoothed out and the temperature gauge is working now. its cold and snowy right now (central arkansas) so im gonna drain the coolant when the weather gets a little better. Thanks for the help everybody.