No heat overheating

[rcopley01]

I have a 2003 Pontiac Grand Am with the 3.4 motor. Last month it started overheating and I had no heat. I replace the thermostat I got good heat and it did not overheat any longer it took me a long time to bleed the air out of the system but everything was working fine again. Yesterday I took the car out and it started overheating again and no heat. Could it be the temperature coolant sensor. Any suggestions would be helpful thank you I am 71 years old and I have cancer and I have to work on the car myself so if you can please help me

 

[melsg5]

No heat in your case is caused by air in the system.
Do the fans run when it's overheating?
Have you pressure tested the cooling system including the cap?