What might indicate the presence of cavitation in a pump?

The presence of cavitation in a pump is often indicated by specific sounds that occur due to the formation and collapse of vapor bubbles in the pump's impeller. These bubbles implode with force, leading to a distinctive rattling or grating noise. This sound is an important warning sign of cavitation, as it can lead to significant damage to the pump if not addressed promptly.

Although fluctuating pressure readings might occur in a system experiencing cavitation, they are not a definitive indicator specific to cavitation. Similarly, foul odors may relate to other issues in the water system and do not typically present a direct correlation to cavitation itself. The rattling sounds provide a more immediate and observable cue, making it the most directly associated indicator of cavitation when compared to the other choices.