Fan Clutch Diagnosis: Looseness
WARNING: This page is about a different car, the 2003 GMC Safari and 2003 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.
Inspect a loose fan assembly for wear. Replace a worn assembly as necessary. Under various temperatures, there is a visible lateral movement at the tip of the fan blade. Allow approximately 6.5 mm (1/4 in) maximum lateral movement measured at the fan tip. More movement is cause for replacement.