Warning! Avoid touching the impeller blades with your hands, tools, or clothing. To avoid injury or equipment damage, do not start the engine if the fan is faulty. Do not attempt to repair broken impeller blades - replace the entire impeller!
Examination
1. Check the fan impeller for cracks, paying particular attention to the condition of the blade bases. A defective impeller must be replaced without fail!
2. Check the fan clutch assembly for signs of leakage and replace if necessary.
3. Rock the impeller in the longitudinal direction; if any play is detected, replace the clutch assembly.
4. Manually rotate the impeller - you should feel a certain resistance, which increases with increasing engine temperature. If the impeller rotates too freely or does not rotate at all, replace the clutch assembly.
5. A description of the procedures for removing and installing the fan assembly is given in Section Removal and installation the engine cooling system fan.