2003 grand am 3.4 changed water pump and thermostat still running hot. Coolant coming out of over flow. What else could be wrong oil is fine no bad head gasket sympsymptoms
Grand ams known for head gasket issues. I would do an exhaust gas test on the coolant just to be sure.
Also did you get all the air out of cooling system after replacing the parts? An air pocket will cause this too.