Does adding water to the car radiator affect the vehicle?
3 Answers
Water can be added to the car radiator. Since water has a relatively high specific heat capacity, its temperature does not rise significantly after absorbing heat from the engine block. Therefore, the engine's heat is dissipated through the cooling water liquid circuit, using water as a heat transfer medium to conduct heat, and then dissipating it via convection through large-area cooling fins to maintain the engine's optimal operating temperature. Below are some radiator maintenance methods: 1. In winter, to prevent freezing and potential core rupture, when parking for an extended period or intermittently, open the radiator cap and drain valve to completely drain the water. 2. When using antifreeze, to avoid corrosion of the radiator, always use long-lasting rust-proof antifreeze produced by reputable manufacturers and compliant with national standards. 3. The radiator should not come into contact with any acids, alkalis, or other corrosive substances.
Using mineral water as a temporary emergency solution is understandable, but never make it a regular practice. The core design of the cooling system actually relies on coolant, which has three key protective properties: a boiling point exceeding 130°C to withstand high temperatures, the ability to remain liquid at -40°C in winter, and most importantly, its anti-corrosion and anti-rust capabilities. Adding water for a short drive of half an hour is generally fine, but prolonged use can cause serious issues. The calcium and magnesium ions in tap water trigger electrochemical reactions with the metal in the radiator. I've seen many water-filled radiators in the workshop with reddish-brown rust deposits coating the inner walls, clogging the cooling fins like constipation. Even more alarming, adding water dilutes the coolant concentration—especially for drivers in northern regions. If the radiator freezes and cracks at -20°C, the repair costs will far exceed a few hundred bucks. Remember to visit an auto repair shop immediately after an emergency to fully replace the coolant.
When I was young, I also thought adding tap water could save money, until one time my old Jetta's temperature gauge turned red on the highway. After being towed to the repair shop and having the engine dismantled, the cylinder head gasket was blown. The mechanic pointed at the thick scale in the radiator and scolded me for being foolish. The cooling system is like human blood vessels, and coolant is a specially formulated blood substitute. Impurities in water form scale when heated, which can clog the tiny pipes in the radiator over time. Especially in turbocharged cars, where engine temperatures can easily exceed a hundred degrees, using water with its lower boiling point doubles the risk of overheating. Now, I even teach my neighbors how to check the freezing point of coolant: use a straw to take a few drops and place them in the freezer; if they don't freeze at -15 degrees Celsius, it's considered qualified. If you really run out of coolant on the road, it's recommended to temporarily use purified water as a substitute, but drain and refill it properly as soon as you get home.
