How to Clean a Car's Radiator?

[JohnFitz]

Car radiator cleaning steps are as follows: 1. First, drain the coolant inside the radiator, prepare a jack, a waste liquid container, and a Phillips screwdriver, then open the engine hood and use the jack to lift one front wheel; ensure the vehicle is safely and stably lifted in drive gear, and the handbrake must be firmly engaged. 2. After draining the waste liquid, screw back the drain plug, but do not apply excessive force when tightening; because drain plugs are mostly made of anti-corrosion plastic material, excessive force may cause the threads to strip. 3. Refill the coolant, with the ratio of water to vinegar controlled between 1:9 or 2:8. 4. Use the coolant to fill from the expansion tank and flush the pipes and radiator slightly. 5. Start the engine.

[LillianRose]

I've thought about cleaning the car radiator quite a few times. The key is to do it after the engine has completely cooled down, otherwise there's a high risk of burns. I usually start by removing the radiator cap and using a soft brush to clean off debris like insects and willow catkins from the surface of the cooling fins. Then I pour a dedicated cleaning agent into the radiator - those citric acid-based ones available on the market work well. Filling it with coolant and letting it circulate for half an hour helps dissolve scale deposits. Afterwards, it's crucial to rinse thoroughly with clean water three or four times until the water runs completely clear. Don't forget to check the rubber hoses for aging cracks, and clean the sealing ring on the radiator cap as well, otherwise it might affect cooling efficiency. When refilling with antifreeze, make sure to bleed all the air out completely - otherwise the engine temperature might suddenly spike while driving, which is a common cause of summer breakdowns.

[MacJonathan]

Cleaning the radiator can actually be done by yourself, with the key point being to avoid directly blasting the fins with a high-pressure water gun as they are quite fragile. Once when I helped a friend, I first disconnected the negative terminal of the battery for safety, then used compressed air to blow away the poplar fuzz stuck between the fins. For cleaning the inner walls, you can buy a radiator descaler, pour it in, and let the engine idle for twenty minutes—the dirt will flush out with the coolant. It's best to use distilled water for rinsing to prevent new scale buildup. Don't forget to check if the fan can spin normally and if the temperatures of the upper and lower radiator hoses are consistent, which can indicate whether the circulation system is blocked. Finally, when topping up the coolant, make sure it's between the MAX and MIN marks, especially in northern winters where the concentration must be sufficient to prevent the radiator from freezing and cracking, which would be a costly mistake.

[Nate]

The core of radiator cleaning is divided into three steps: pre-treatment, chemical reaction, and rinsing inspection. I usually start by removing the protective cover to clean the exterior of the radiator grille, making sure to pick out any branches or leaves. Soak it with a weak alkaline cleaner for half an hour to dissolve the scale, and starting the engine midway helps circulate the liquid for better results. During high-flow rinsing, observe the color change of the outflowing water—it should turn from cloudy to clear to meet the standard. Before adding new antifreeze, it's advisable to test the freezing point, especially for older cars, and adding a bottle of radiator protector is recommended. The entire process requires gloves and goggles, as coolant is toxic and must not come into contact with the skin. Regular radiator cleaning can save fuel, and cars with poor cooling efficiency may even experience weaker air conditioning performance.