What are the reasons for the decrease in antifreeze over time?

[GenesisLee]

Reasons for the decrease in antifreeze over time: 1. The engine operating temperature is too high, causing some antifreeze to evaporate. 2. There may be cracks in the cylinder gasket or cylinder block, allowing antifreeze to enter the engine and be burned off. 3. There might be a leak in the cooling system, causing continuous antifreeze leakage. Below is some relevant information about antifreeze: The main functions of antifreeze are to cool the engine and provide anti-rust protection, among others. It is primarily composed of a mixture of water, ethylene glycol, propylene glycol, and other compounds, with specified boiling and freezing points. Particularly important is the freezing point of the coolant, generally around minus forty degrees Celsius.

[StValeria]

As someone who has driven for many years, I find it quite common for antifreeze levels to drop. The main reason is thermal evaporation: when the engine runs at high temperatures, some of the liquid vaporizes and is lost, especially during summer when the air conditioning is running at full blast. Another cause is minor leaks—aging radiator connections or hoses may seep a little, leaving no visible traces on the ground but causing a gradual drop in fluid level. Internal consumption is more troublesome, such as when a cylinder head gasket fails, allowing coolant to seep into the combustion chamber and burn off, resulting in white smoke from the exhaust and reduced engine power. Air bubbles being purged can also cause a slight initial drop in fluid level, which is normal. I make it a habit to check the level monthly when the engine is cold, topping it up with the same type of antifreeze to prevent scaling from mixing different types. Ignoring this can lead to poor heat dissipation, overheating, and even engine damage, costing thousands to repair. Checking before long trips can save you a lot of money.

[MichaelRose]

From a repair perspective, coolant loss can be attributed to three main causes: Evaporation occurs when the liquid naturally vaporizes under high temperatures, especially in new engines with higher thermal efficiency. Leakage is commonly caused by aging or cracked seals in water pumps or hoses; even new vehicles may experience loose assembly. Internal issues, such as a damaged head gasket, can lead to coolant entering the combustion chamber, resulting in faster consumption and sweet-smelling exhaust. A slight drop in coolant level after air bubbles are purged is normal. Inspection methods: Use a pressure tester to locate leaks or check for emulsified oil under the cap when the engine is cold, indicating mixing. It's recommended to flush and replace the coolant every six months to prevent corrosion and clogging. Excessive loss affects cooling efficiency and increases overheating risks—always perform checks when the engine is cold. Use OEM or compatible replacement parts to avoid further issues and prevent costly engine damage.

[JasmineDella]

Low antifreeze levels pose significant risks. Leaks or evaporation causing fluid loss can lead to insufficient engine cooling, increasing the risk of overheating and spontaneous combustion. Particularly during high-speed long-distance driving, if the temperature gauge rises sharply, you must stop immediately to cool down; otherwise, the engine may seize, parts may deform, and repairs can be costly. Prevention is key: regularly check the fluid level when the engine is cold by opening the cap and using the dipstick to ensure it's within the marked lines. If the level drops rapidly in a short period, inspect the chassis for leaks or abnormal oil color and visit a professional repair shop promptly. Never mix antifreeze with tap water, as this can cause scaling and worsen the problem. I emphasize safety first—when topping up the fluid, wear gloves to prevent burns from the hot engine. Make it a habit to perform maintenance every season to extend your vehicle's lifespan and drive with peace of mind.