Most often, a noisy fan belt is an indication that it is worn down and should be replaced. If the belt is not supported by a spring-loaded or hydraulic tensioner, the noise may indicate a need for manual adjustment. Ignoring these signs and not addressing the issue promptly can lead to further damage to the engine components and potentially result in more costly repairs down the line. Regular fan belt maintenance and timely belt replacements are essential to ensure optimal performance and longevity of your vehicle.