How often should the water in a car's radiator be changed?
2 Answers
The liquid inside a car radiator is not ordinary tap water, but coolant (antifreeze), which generally needs to be replaced every two years. Antifreeze: The full name should be antifreeze coolant, meaning a coolant with antifreeze function. Antifreeze is a special additive-containing coolant primarily used in liquid-cooled engine cooling systems. It has excellent properties such as preventing freezing in winter, boiling in summer, and protecting against scale and corrosion year-round. Antifreeze quality: If the antifreeze is of poor quality or even counterfeit, it won't serve its intended purpose. Coolant is prepared by mixing antifreeze with water in specific proportions. Automobile manufacturers usually specify in user manuals the mixing ratios for different low-temperature antifreeze grades and designate the antifreeze model, which cannot be mixed arbitrarily.
I've been driving for decades, and the radiator fluid, also known as coolant, should generally be replaced every two years to be on the safe side. The exact timing depends on your car's manual recommendations. Most regular cars suggest replacement around every two years or 30,000 kilometers, while long-life types might last up to five years—but don't take it lightly. Why replace it regularly? Old coolant loses its corrosion inhibitors, leading to rust and clogging in the radiator and engine internals, severely affecting cooling efficiency. During summer, long drives in high temperatures can cause engine overheating, and in severe cases, piston seizure and engine failure. In winter, reduced antifreeze capability can freeze and crack pipes, costing a fortune to repair. Have the mechanic check its color during each service—clear and transparent is fine, but if it turns yellow or becomes cloudy with sediment, replace it early. Don’t use cheap products; opt for reputable coolant brands, and avoid diluting it with water, as it affects performance. Replacing it during routine maintenance is safe, hassle-free, and cost-effective—far better than dealing with major repairs later.
