Final answer:
The thermostat is the component of the cooling system that controls the flow of coolant, regulating engine temperature by opening and closing based on the engine's needs.
Step-by-step explanation:
The part of the cooling system that controls the flow of coolant is the thermostat. The thermostat is a temperature-sensitive device that opens and closes to regulate the coolant flow based on engine temperature. When the engine is cold, the thermostat remains closed to allow the engine to warm up quickly.As the engine reaches its operating temperature, the thermostat opens up to allow coolant to flow through the radiator, thereby helping to maintain a consistent engine temperature by dissipating excess heat.
Other key components of the cooling system include the heater core, which provides heat for the cabin, the radiator, which cools the coolant by allowing heat to escape into the air, and the water pump, which circulates coolant throughout the system. However, the thermostat is uniquely responsible for controlling the flow of coolant.