Why Does Car Antifreeze Overflow?
2 Answers
Antifreeze is an important consumable in the cooling system. The car cooling system is an essential component for vehicles, as it helps maintain a stable output power for the engine. Many car owners have encountered situations where antifreeze overflows from the reservoir. The reasons for this can be summarized into three points: 1. Damaged Cap: Check if the reservoir cap is damaged. If the cap is damaged, antifreeze may leak out due to the high temperature inside the reservoir. 2. Overfilled Antifreeze: If the antifreeze level exceeds the marked line on the reservoir, it may overflow during driving. No overflow occurs when the antifreeze level is appropriate. 3. Thermostat Malfunction: A faulty thermostat can cause the water temperature to rise excessively. When the water temperature is too high, the coolant cannot enter the engine's water passages for a full circulation, leading to a small circulation in the radiator and resulting in antifreeze overflow.
Last time I was driving on the highway, I encountered coolant bubbling out from the overflow tank, which scared me so much that I immediately pulled over. Later, the mechanic explained that it was caused by excessive pressure in the cooling system. Common causes include aging or leaking seals on the radiator cap, overfilling of coolant, or a stuck thermostat leading to poor circulation. This is especially prone to happen during summer heat when coolant expands and contracts more significantly. In my case, the issue was due to a cracked rubber seal on the radiator cap, causing the pressure valve to fail and leading to overflow. The mechanic advised me to regularly check the radiator cap and coolant level, ensuring the fluid stays between the MAX and MIN marks when the engine is cold for optimal safety. If there's a severe leak, never force the car to keep running—it could lead to engine damage, which would be a huge loss.
