My 2002 Saturn sl1 is inconsistently over heating. The thermostat is out and it ran fine for 3 months. Then I put new coolant in at 50/50 and it started overheating. I may not have drained it properl
You may have air in the system, leave the radiator cap off and start the car and let it run until the thermostat opens and you see the water . This procedure should remove the air from the system
If I was you I'd start over I would put some cleaner chemical in there and bake it into the system then power flush the entire system put brand new coolant in brand new thermostat you know fill and bleed the air out of the system properly so my advice is to start over and you should first of all pressure test the system to see you if it's holding pressure you know your whole entire cooling system does if you have a leak somewhere that could really be the main issue good luck.
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