How to Clean a Car Radiator

After a while, car radiators can become clogged with calcium deposits and rust. Cleaning a car radiator will keep your radiator in great working condition. A clogged radiator results in reduced cooling efficiency, damage to cooling components and may even lead to engine overheating. Cleaning a car radiator should be done once every 24 months.

1. Drain the radiator. 


2. With the engine cool, remove the radiator cap and remove the drain plug on the underside of the radiator.


3. Let the liquid drain from the radiator.


4. Replace the drain plug and fill the radiator with water.


5. Turn on the engine and let the engine get hot to allow the thermostat to open up and the water to circulate through the engine.


6. Cool the engine. 


7. Remove the drain plug and cap. 


8. Drain the water and replace the plug.


9. Fill the radiator with water and add a cooling system cleaner or radiator flush. Use only products that are recommended for the vehicle.


10. Turn the engine and the heater on. Flush for the recommended time according to the manufacturer.


11. Cool the engine and drain the radiator.


12. Fill the radiator with distilled water. Turn the engine on and let it heat up until the water flows through the engine block. Let it cool and drain. It is a good idea to do this at least twice to be sure that the entire cleaner has been removed from the radiator.


13. Add antifreeze at a 50 to 70 percent concentration.  Add distilled water to the radiator until filled.  


14. Run the engine, cool, and top off with antifreeze.


15. Fill the reservoir with antifreeze to the indicator level.