Let the engine cool completely before opening the hood to avoid burns from hot components.
Open the coolant reservoir and check the coolant level; it should be between the min and max marks.
Inspect the radiator cap for cracks or worn seals that could cause pressure loss.
Start the engine and let it idle while monitoring the temperature gauge on the dashboard.
Observe if the radiator fan activates when the engine reaches operating temperature.
Use an OBD2 scanner to check for any stored trouble codes related to the cooling system.
Locate and inspect the radiator fan fuse and relay; replace if blown or faulty.
Test the coolant temperature sensor using a multimeter or by monitoring live data via OBD2.
Look for visible coolant leaks around hoses, the radiator, and the water pump area.
Check if the upper radiator hose gets hot; if not, the thermostat may be stuck closed.
Remove and test the thermostat in hot water to see if it opens properly, if suspected faulty.
Flush the cooling system if the coolant appears rusty, dirty, or contaminated.
Refill the system with a 50/50 mix of coolant and distilled water using a coolant funnel.
Bleed the cooling system to remove air pockets that could cause overheating.
Reinstall the radiator cap securely and ensure it seals properly.
Start the engine again and monitor for signs of overheating at idle.
Verify that the radiator fan now operates correctly when the engine warms up.
Check the temperature gauge to ensure it stays within normal range during idle.
Inspect the serpentine belt to ensure it is intact and driving the water pump.
Test drive the vehicle briefly and recheck coolant level after cooling down.
