What Causes the Coolant Level to Drop When Hot and Recover When Cold?

[StBennett]

The reason for the coolant level dropping when the engine is hot and recovering when cold is due to the activation of the heater during startup, which utilizes the circulation of antifreeze to maintain the engine at a constant temperature. Here are some related details about coolant: 1. Winter Antifreeze: To prevent the coolant from freezing and causing the radiator or engine block to crack when the car is parked in winter, the freezing point of the coolant should be about 10°C lower than the lowest temperature in the region, preparing for sudden weather changes. 2. Selection and Addition: Choose a coolant with the appropriate ratio based on specific conditions. When adding coolant, fill the radiator until the liquid level reaches the designated position. 3. Anti-Corrosion and Scale Prevention: Coolant helps prevent corrosion of metal components and aging of rubber parts. During circulation, it reduces scale formation, avoiding blockages in the circulation pipes and ensuring the cooling system's heat dissipation function.