What does a fuel system’s water separator do?

The function of a fuel system's water separator is to remove water from the fuel before it reaches the engine. Water can enter the fuel system through various means, such as condensation in the fuel tank or from contaminated fuel. If water is present in the fuel, it can lead to engine performance issues, such as difficulty starting, rough running, and potential damage to injectors and combustion chambers.

The water separator operates by utilizing gravity or coalescing elements to separate the water from the fuel. The heavier water accumulates at the bottom of the separator, while the cleaner, drier fuel is allowed to pass through to the engine. This crucial role helps maintain engine efficiency and longevity, ensuring that only the appropriate fuel mixture is delivered for combustion.

In contrast to the other choices, increasing fuel pressure, removing dirt from the fuel, or adding additives are functions associated with different components in the fuel system or fuel treatment processes, but they do not pertain directly to the water separator's main purpose. The water separator specifically targets the removal of water, making choice C the correct answer.