Can You Add Pure Water When the Car Coolant Is Insufficient?
2 Answers
Coolant insufficiency can be temporarily addressed by adding pure water, but this should only be done in emergencies, and the coolant should be replaced with new coolant as soon as possible afterward. The composition of coolant includes water, antifreeze, and other components. During the manufacturing process, water and antifreeze are mixed in specific proportions. Adding additional water to the coolant can disrupt this balance, increasing the water ratio and lowering the coolant's freezing point. In cold weather, this can cause the antifreeze properties to fail, potentially damaging the radiator and leading to freezing of the engine's cylinder head and block. In emergency situations, besides pure water, distilled water can also be added. However, mineral water must never be used. Mineral water contains minerals that can react with the coolant's components, impairing its effectiveness. Similarly, after the emergency has passed, the coolant should be replaced with new coolant as soon as possible.
I've been driving for over a decade, and I've actually used purified water in emergencies when coolant was insufficient. That time during a trip, the water temperature gauge went off the charts, so I added water at a service area to temporarily cool it down and drove to a repair shop. But later, I was lectured that purified water lacks the anti-corrosion additives found in specialized coolant, making aluminum and iron components in the engine prone to rust or corrosion. Over time, this could lead to hose leaks or radiator blockages. Especially in winter, pure water can freeze, expand, and crack pipes, while in hot weather, its lower boiling point can cause overheating accidents. It's advised to add only a small amount of purified water in emergencies as a buffer and switch back to standard coolant mixture as soon as possible. For self-maintenance, keeping a bottle of emergency coolant on hand is more reliable to avoid regrets. Regularly check the system's fluid levels and top up with specialized products early if low to protect the engine's lifespan.
