Why Does the Antifreeze in the Car Decrease?
2 Answers
The main reason for the decrease is natural evaporation, with normal consumption being about half a liter per year. Rapid consumption may be caused by leaks or poor circulation, with leaks accounting for about 80% of the cases. Method for Replacing Antifreeze: Before completely replacing the antifreeze, conduct a thorough inspection to check for any signs of leaks or cracks in the pipes, with a focus on the five-way water pipe. The five-way pipe gets its name from having five connecting interfaces for different parts. Antifreeze flows through the five-way pipe and is then distributed to various parts of the car to function. If there are signs of antifreeze leakage in this part, replace the water pipe or re-secure the interface as needed. Drain the old antifreeze and then flush the liquid channels with clean water. Add clean water to the antifreeze reservoir, then continue filling the reservoir with water to allow it to flow continuously through the engine cooling system. Start the engine and let it idle for 3 to 5 minutes to circulate the water. Initially, the water flowing out of the reservoir will be slightly pinkish. Continue adding clean water until the water coming out is clear. Note: Do not forget to remove the heater hose and drain the water from the heater core. About an hour after draining, add the new antifreeze through the radiator hose to allow it to flow quickly into the radiator. Then add another bucket of antifreeze to the antifreeze reservoir until it is nearly full. Start the engine and let it run for about 10 minutes. During this time, the coolant level will drop slightly as air is expelled from the cooling system. Top up the antifreeze to the "MAXT" mark on the reservoir.
Having driven for so many years, it's common for the coolant level to drop, mostly due to minor leaks. For instance, if the radiator hose connection becomes loose from aging or a rubber hose develops a small crack, the fluid slowly seeps out—you might notice wet spots when parked on the ground. In summer, high-speed driving raises temperatures, causing some coolant to evaporate. But as long as the loss is minimal and within normal limits, the car runs fine. Another possibility is a loose radiator cap seal; if pressure drops, coolant escapes through the overflow tank—try tightening it yourself first. A more serious issue is a blown engine head gasket, where coolant leaks into the combustion chamber and burns off, indicated by white exhaust smoke—stay alert. I recommend regularly checking under the car for leaks in the chassis or engine bay to catch problems early and avoid costly repairs. Generally, check the coolant level every six months. When topping up, use the same brand to prevent mixing and potential solidification clogging the system—safety comes first.
