Is it normal for the coolant level to rise when the engine is hot?
1 Answers
It is normal for the coolant level to rise when the engine is hot because, in this state, the engine water temperature increases, causing the coolant to expand, which results in a higher coolant level. Under normal circumstances, the coolant is stored in both the main reservoir and the overflow tank, with the overflow tank only filled halfway or kept between the minimum and maximum level marks. When the engine is hot, the overflow tank can accommodate the expanded coolant. However, if the overflow tank is already full, some coolant may spill out during hot conditions, leading to waste. Therefore, it is essential to strictly follow the coolant refill requirements. Generally, conventional coolant should be replaced every 2 years or approximately 40,000 kilometers. For commercial vehicles (e.g., taxis), it is recommended to replace the coolant annually. Long-life coolant, on the other hand, can last for over 3 years. If suspended particles, sediment, or signs of deterioration are observed in the coolant, it should be flushed and replaced. Many people mistakenly believe that coolant is only necessary in winter, but this is not the case. Coolant is required year-round as it serves the dual purpose of preventing freezing in winter and overheating in summer. It protects the engine's cooling system, improves heat dissipation, and enhances engine efficiency.
