However, when the engine is turned off, the water pump stops circulating the coolant, and the thermostat remains closed, preventing any further flow. As a result, the coolant trapped in the engine block and cylinder head can continue to absorb heat from the engine components, leading to a gradual increase in temperature.
During cold weather, the ambient temperature is already low, and the rate of heat dissipation from the engine is slower compared to warmer conditions. This can exacerbate the issue of trapped heat, causing the engine to remain relatively warm even after being turned off.
Factors such as engine size, type, and ambient temperature can influence the exact duration of this residual cooling period. Additionally, certain design characteristics, such as the engine block material and coolant composition, can also impact the rate of heat retention and dissipation.
In summary, the cooling system's reliance on active circulation during engine operation means that it becomes less effective in removing heat when the engine is turned off, resulting in a gradual rise in engine temperature, especially during cold weather conditions.
