What is one of the key parts to inspect for proper function in the engine compartment?

The timing belt is indeed a crucial component to inspect for proper function in the engine compartment. It plays a vital role in synchronizing the movements of the engine's crankshaft and camshaft, ensuring that the engine's valves open and close at the appropriate times during the combustion cycle. If the timing belt fails, it can lead to severe engine damage, making its inspection vital.

While the starter motor and power steering pump are also important components, the timing belt is specifically and directly related to the engine's operational integrity. Therefore, it's not unusual for a higher emphasis to be placed on its inspection during a pre-trip evaluation.

Considering the broader context, all components within the engine compartment should be inspected, but the timing belt carries particular significance due to its fundamental role in engine performance.