Check the coolant level.

Check for any engine coolant leakage (from gaskets, hoses, O-rings, etc.).

Check for dirt, leaves, or insects on the radiator and the A/C condenser.

Check for deteriorated coolant.

Check for a damaged or deformed fan shrouds.

Check the fan motors are operating properly (air should be blowing toward the engine).

Inspect the fan motors or fan relays.

Check the radiator cap.

Check the thermostat.

Inspect the water pump.

Check for plugged or deteriorated radiator hoses.

Check for clogged radiator.

Check for a plugged heater core or hoses.

Check for a damaged cylinder head gasket.