What to Do If Different Types of Coolant Are Mixed?
2 Answers
If different types of coolant are mixed, you need to completely drain the coolant from the radiator, flush it with purified water, and then refill it with new coolant. It is essential to use the same brand of coolant. Different brands of coolant may have varying production formulas, and mixing them can lead to chemical reactions between additives, potentially causing them to become ineffective. How to choose coolant: The basic indicators of coolant are its freezing point and boiling point. Coolants available on the market come in specifications such as -15°C, -25°C, -30°C, and -40°C freezing points. Generally, it is advisable to choose a coolant with a freezing point at least 10°C lower than the lowest temperature in your region. How to check if coolant is low: Observe the coolant warning light on the dashboard. If it lights up, it may indicate low coolant levels, though it could also be due to excessively high engine temperatures. Check the coolant reservoir. If the fluid level is below the minimum mark (MIN), do not continue driving; add coolant promptly. Inspect the water level markings on the coolant overflow tank. The coolant level should normally be between the maximum and minimum marks. If the coolant level is below the minimum mark, it indicates a shortage of coolant.
That time I accidentally mixed a bit of antifreeze of different colors, and after driving for a week, the temperature gauge shot up a bit. The mechanic found that a chemical reaction had clogged the small holes in the radiator. I had no choice but to spend money to flush the entire cooling system clean and switch to a single brand of antifreeze. Since then, I always check the type and color on the bottle first. Mixing might not show immediate effects, but over time it can corrode internal engine parts and even damage the water pump—it’s best not to delay dealing with it. If you accidentally mix them, first monitor whether the car’s temperature stays stable. If everything seems fine, take it to a professional shop to flush the system with distilled water and refill with new fluid—it’ll cost around a hundred bucks. Antifreeze isn’t just for winter; it also helps with cooling in summer. So if you mix them, don’t wait too long. Regularly replacing antifreeze can also prevent this issue, avoiding bigger unexpected expenses.
