Which component opens and closes the engine's valves?

The camshaft is the correct component responsible for opening and closing the engine's valves. It plays a crucial role in the engine's operation by controlling the timing and duration of valve movements in correlation with the engine's cycles. The camshaft has lobes that push against the valves or their associated rocker arms. As the camshaft rotates, these lobes lift the valves off their seats, allowing air and fuel to enter the cylinder during the intake stroke and enabling exhaust gases to exit during the exhaust stroke.

The crankshaft, on the other hand, is primarily responsible for converting the linear motion of the pistons into rotational motion, which powers the vehicle. The intake manifold is a component that delivers the air-fuel mixture to the engine cylinders but does not control the opening and closing of the valves. The ignition coil is integral to the ignition system by supplying voltage to the spark plugs but does not interact with the valve mechanism. Understanding the role of the camshaft is essential for anyone studying engine mechanics, as it directly affects engine performance and efficiency.