Water pump not pumping or a pluged radiater
Is vehicle actually overheating? Could be a bad temperature sending unit or gauge Check temperature with a thermometer If thermostat does not open vehicle will overheat
Inoperative cooling fan(s) Bad thermostat Bad fan switch sending unit Bad fan relay Blocked radiator cooling tubes (internally)
If it's not blowing out all of the coolant in a short period of time, you probably have a bad water pump. On the other hand, if you ARE blowing out all of the coolant, it's probably a damaged head gasket.
maybe try flushing the cooling system, or replace temp sending unit.
Temperature Gauge Sending Unit The sending unit is located in the front section of the manifold in the vicinity of the thermostat.
The temp sending unit may be at fault.
The coolant temperature sensor is near the thermostat outlet at the front of the engine. You are facing the engine. It should be located to the right of the thermostat outlet. The sending unit on the left of the thermostat outlet, is the temperature gauge sending unit.
Temp sending units in general (not always) are usually found close to the thermostat.
Next to the thermostat housing.
Temperature Gauge Sending Unit The sending unit is located in the front section of the intake manifold in the vicinity of the thermostat.
Just to the side of the thermostat housing.Just to the side of the thermostat housing.
Didn't mention the year or engine size but temp sending units are generally found close to the thermostat.