What Causes Coolant to Boil?

[Walter]

There are several reasons why a car may lose coolant due to boiling: 1. Radiator Cap Damage: If the radiator cap on the cooling system malfunctions, causing the steam valve to open at too low a pressure or remain constantly open, it can lead to significant steam leakage, resulting in coolant loss over time. 2. System Leakage: After prolonged driving, various parts of the car's cooling system may develop leaks, potentially causing coolant loss. 3. Engine Overheating: Continuous high temperatures or overheating of the engine can cause the coolant to boil and vaporize. A large amount of coolant may then escape through the radiator cap's steam valve, leading to coolant depletion. 4. Low Cooling Efficiency Due to Low Water Level: Checking the water level in the radiator is a routine daily task. When adding water, ensure it is not overfilled; the level should be between the maximum and minimum marks. 5. Non-Compliant Coolant: If the coolant does not meet the required standards, its boiling point may be too low, or its evaporation rate too high. During operation, excessive water evaporation can increase internal system pressure, leading to coolant loss.