What to Do If Coolants Are Mixed?
2 Answers
If coolants are mixed, it is necessary to completely drain the coolant from the radiator, then rinse it thoroughly with pure water, and refill it with new coolant. Different colors and brands of antifreeze may have different chemical compositions, and mixing them can easily cause adverse reactions, leading to reduced antifreeze effectiveness. It may even generate flocculent substances that can clog the cooling system. In severe cases, it can cause abnormal corrosion to the engine water channels and cooling pipes. Antifreeze prevents the coolant from freezing and expanding during cold seasons, which could crack the radiator or damage the engine cylinder block. Coolant should be used year-round. As part of regular vehicle maintenance, the engine antifreeze should be replaced annually.
Last time I accidentally mixed two different colors of coolant, one blue and one green. I looked it up online and realized this could cause serious problems. Mixing them can lead to chemical reactions, creating sediment that clogs the pipes and even corrodes engine components. While driving, the water temperature suddenly spiked. I immediately pulled over to check if the coolant had changed color or started bubbling. My advice is to avoid long-distance driving right away and find an open area to turn off the engine. The simplest solution is to take your car to a professional auto repair shop for a system flush—they’ll rinse it thoroughly with water multiple times, drain it completely, and refill it with new coolant. To prevent this in the future, always check the coolant label before adding any and avoid mixing different brands. During regular maintenance, monitor the coolant level and color—mixing coolants can be a minor or major issue, so don’t delay addressing it.
