When should you check the engine coolant levels?

Checking the engine coolant levels when the engine is cold is crucial for safety and accuracy. When the engine is warm, the coolant system is under pressure, and opening the coolant reservoir can lead to burns from hot steam or liquid, posing a safety risk. Checking the levels when the engine is cold allows for a safe inspection without the risk of injury.

Furthermore, allowing the engine to cool down provides a more accurate reading of the coolant level. This is important because coolant expands when heated, and a reading taken while the engine is warm may give a misleading level, potentially leading to misunderstandings about whether the coolant needs to be added.

In contrast, checking only when the coolant light is on does not allow for proactive maintenance and could lead to overheating if the levels are already too low at that point. Making it a habit to check before every trip, while beneficial for overall vehicle maintenance, may not be necessary if you are monitoring levels regularly. Therefore, conducting a coolant level check when the engine is cold is the best practice for safety and accuracy.