Can Coolant Be Mixed with Water?
2 Answers
Coolant should not be mixed with water. Here are some key points: 1. Adding water to coolant will lower its boiling point, potentially causing the vehicle to overheat, while also increasing its freezing point. 2. When adding coolant, pay attention to the quantity—neither too much nor too little. There are usually level marks on the coolant reservoir. Adding too much may cause overflow, and since coolant has corrosive properties, it could damage rubber components in the vehicle. Adding too little may lead to engine or radiator freezing in cold weather, even causing cracks, and it won’t provide sufficient cooling, potentially resulting in engine knocking. The ideal level is between the maximum and minimum marks.
I've been driving for over a decade, and I think adding water to coolant depends on the situation. If your radiator boils over on the road and you're really in a pinch, adding some purified water as an emergency measure is acceptable—it's better than letting the engine run dry. But using tap water long-term is absolutely not okay! Tap water contains minerals that will form scale deposits in the pipes when heated, potentially clogging them up like a sewer pipe in just three months. My neighbor didn't believe me and used well water instead of coolant—ended up spending over 4,000 yuan to fix a cracked radiator in winter. Remember, if you add distilled water in an emergency, you must completely flush and replace the coolant within a month, or else metal components will corrode and repairs will cost even more.
