Is It Harmful to Add Too Much Car Antifreeze?
2 Answers
Adding too much antifreeze from reputable brands is not harmful. The excess antifreeze will expand due to heat during vehicle operation and overflow through the pressure relief valve, causing no harm other than leaving some stains. However, it is best to use a syringe to remove the antifreeze above the maximum water level. Some low-quality antifreeze produced by inferior manufacturers is corrosive, which not only damages the cooling system but also harms the wiring and other components in the engine bay when the excess antifreeze overflows. In severe cases, it can even corrode the radiator and flow into the engine. Vehicle antifreeze generally needs to be replaced every 2 years or 40,000 kilometers. This is just a reference interval. For commercial vehicles with higher mileage, the replacement interval should be shorter. Since driving conditions vary for each vehicle, the replacement should be based on actual usage. Check the antifreeze level regularly and top it up promptly if it is low. If suspended particles, sediment, or discoloration are observed in the antifreeze, replace it immediately and clean the system. Methods to determine if antifreeze is low: Observe the antifreeze warning light on the dashboard. If it lights up, it is likely due to low antifreeze, though it could also be caused by excessively high engine temperature. Check the antifreeze reservoir. If the level is below the minimum mark (MIN), do not continue driving and add antifreeze promptly. Check the water level markings on the antifreeze tank. The normal antifreeze level should be between the maximum and minimum marks. If the antifreeze is below the minimum mark, it indicates a shortage.
Adding too much antifreeze is indeed harmful, and I'd like to share some experience. In the past, my car had excessive antifreeze added during maintenance, which caused the cooling system pressure to skyrocket, resulting in the expansion tank overflowing and coolant leakage. This not only wastes money but may also damage the water pump seal, and long-term corrosion of engine components can be even more troublesome. The cooling system is designed with expansion space, so being slightly overfilled is fine, but you need to be careful if it's full. I recommend checking the fluid level between the min and max lines before each refill. If you find it too high, use a syringe to remove the excess or take it to a professional shop. During regular maintenance, also check the color and concentration to ensure it can prevent freezing and boiling. Decades of driving experience have taught me that overfilling any fluid is unwise—it can hinder the system's operation and increase the risk of pipe bursts. Develop a habit of checking every quarter for safety and cost savings.
