Hi all, I have a 2003 Monte Carlo and it recently having problems with the heater and ac not working. It usually runs and idles at around 170 degrees but recently even when driving it will fluctuate between 200 and 210 degrees. Are the problems related? It's not in the red, but even on short trips like 10 miles when it is 20 degrees outside it is getting hot.

 

sounds like there is air in the system, most commonly a flush can fix that, but if you have a gasket issue, and air is getting into the system in another way, you will have to repair that first.