Whirring Sound There is a small electric-pump that pumps 3 liters of coolant into a thermal container (to keep it hot) every time you turn the hybrid system power OFF. When the power is turned back ON, the coolant is pump back into the engine. This process reduces emissions, by achieving warm-up much faster than with an engine that would normally have to heat itself up. This process also helps to reduce wear & tear on the engine.
- posted
15 years ago