I had overheating issues for a while know. Replaced the thermostat and housing. Also replaced ignition coils. Bleed the system 3 times and every day I wake up to an empty reservoir.
My Chevrolet sonic still overheats, even though I replaced the radiator, thermostat, engine coolant sensor, thermostat housing. It is still showing error code 89. Can it be that the heater core inside the motor needs to be replaced