When the coolant system thermostat is closed, coolant is allowed to flow to

When the coolant system thermostat is closed, coolant is allowed to flow to

• A. Water pump
• B. Radiator
• C. Heater core
• D. Engine block

Answer: (A)

When the thermostat is closed, its job is to stop coolant from moving to the radiator. To keep the engine warmed and prevent a cold start from overheating, the coolant is kept circulating in a bypass loop that returns to the pump. The component that drives this circulation is the water pump, so the coolant continues to flow to the water pump as part of the closed-loop path. The radiator is bypassed until the thermostat opens, and while the engine block is part of the circulating path, the question focuses on where the flow is effectively maintained, which is driven by the water pump.

When the thermostat is closed, its job is to stop coolant from moving to the radiator. To keep the engine warmed and prevent a cold start from overheating, the coolant is kept circulating in a bypass loop that returns to the pump. The component that drives this circulation is the water pump, so the coolant continues to flow to the water pump as part of the closed-loop path. The radiator is bypassed until the thermostat opens, and while the engine block is part of the circulating path, the question focuses on where the flow is effectively maintained, which is driven by the water pump.