On my 2003 dodge stratus se sedan 4 cyl dohc.. Car started overheating and also blows cool air when heater is on. I just changed thermostat and refilled antifreeze and iwhen tested was blowing hot air then drove for about 15 minutes and started to notice was blowing cool air again then overheated, pulled over and had to add water let ccol for a few minutes tried again and same thing so parked and went back several hours, filled up and drove 4 miles to home. What can i check and what possible issues may it be? Please advise..

These cars can also get what are called air pockets in the engine. When you add fluid to the radiator it must be done slowly. You will noice air bublles( large ones surfacing while adding dfluid to the radiaor. This is probably what is casusing it to over heat and not blow hot air. you have an air pocket which is causing it to not flow properly. Subaru engines are extremely prone to this also!! Open the system and add anti freeze and check the fluid level. take your time. It will take some time to get the air pockets out of the engine. let me know if this helps you out further. Sosunds good that you found no water in the oil! TOM These cars can also get what are called air pockets in the engine. When you add fluid to the radiator it must be done slowly. You will noice air bublles( large ones surfacing while adding dfluid to the radiaor. This is probably what is casusing it to over heat and not blow hot air. you have an air pocket which is causing it to not flow properly. Subaru engines are extremely prone to this also!! Open the system and add anti freeze and check the fluid level. take your time. It will take some time to get the air pockets out of the engine. let me know if this helps you out further. Sosunds good that you found no water in the oil! TOM