What are the symptoms of a bad car water pump?

[OBrynlee]

When a car's water pump fails, the symptoms include: unstable engine idle, coolant leakage, and increased engine operation noise. During regular vehicle use, it's important to change the coolant periodically. Prolonged use of old coolant can damage the water pump. For household vehicles, the coolant should be replaced every two years. When coolant is low, never use tap water as a substitute. Tap water contains minerals that can form scale when heated, potentially clogging the engine's water passages. Car engines widely use centrifugal water pumps, whose basic structure consists of the pump housing, connecting plate or pulley, pump shaft and bearings or integrated shaft bearings, pump impeller, and water seal assembly. These components are essential parts of the automobile.