What is a possible symptom of a liquid pump cavitating?

When a liquid pump is cavitating, it typically produces a distinctive sound that resembles grinding or hitting rocks. This noise arises from the formation and subsequent collapse of vapor bubbles within the pump. Cavitation occurs when the pressure in the pump falls below the vapor pressure of the liquid, causing the liquid to vaporize. As these vapor bubbles travel through the pump and enter areas of higher pressure, they collapse violently, creating shockwaves that generate the characteristic noise. This phenomenon not only causes audible symptoms but can also lead to significant damage to the pump over time.

The other options, while not characteristic of cavitation, provide contrasting conditions that do not suggest pump cavitation. Stable motor amperage indicates that the pump is operating under normal conditions without the irregular fluctuations associated with cavitation. Also, a differential reading would be expected to change during cavitation, and a quiet and smooth-sounding pump generally suggests it is functioning well, free of cavitation issues.