Fan Clutch Diagnosis: Noise

Sometimes fan noise is present under the following conditions:

• The clutch is engaged for maximum cooling.
• The noise is present the first 15 seconds to 1 minute after start-up. This condition occurs until the clutch can redistribute the silicone fluid to the normal disengaged operating condition (after setting 2-4 hours).

Fan noise or an excessive roar generally occurs under all high-speed conditions (2,500 RPM or higher) if the clutch assembly is locked up due to internal failure. If the fan cannot be rotated by hand or there is a rough grating feel as you turn the fan, replace the clutch. Refer to FAN REPLACEMENT .