Caution: To help avoid personal injury or damage to the vehicle, a bent, cracked, or damaged fan blade or housing should always be replaced.

Fan noise is sometimes evident under the following normal conditions:

Fan noise or an excessive roar generally occurs continuously under all engine speed conditions of 2500 RPM and up. This occurs if the clutch assembly is locked up due to an internal failure. If you cannot rotate the fan by hand or if there is a rough grating feel as you turn the fan, replace the clutch. Refer to Fan Replacement .

Inspect a loose fan assembly for wear. Replace the fan assembly as necessary. There is a visible lateral movement at the tip of the fan blade under various temperature conditions. Approximately 6.5 mm (¼ in) maximum lateral movement measured at the fan tip is allowable. This is not cause for replacement.

A small fluid leak may occur in the area around the bearing assembly. The fan blade clutch operation is not affected by small fluid leaks. If leakage appears excessive, replace the fan clutch blade. Refer to Fan Replacement .

1. Start with a cool engine in order to ensure that a complete fan blade clutch disengagement.
2. Replace the clutch if the fan and clutch assembly freewheels with no drag. This occurs when the assembly revolves more than 5 times when you spin the assembly by hand. The clutch will freewheel when you hold the small hub with one hand and rotate the aluminum housing. This is a normal condition. This condition is not considered a test for replacement. If the clutch performs properly with a slight drag, go to the next step. Refer to Fan Replacement .

Notice: Check for adequate clearance between the cooling fan blades and the test thermometer before starting the engine, as damage could occur.

3. Place a thermometer between the fan blades and the radiator. Insert the thermometer sensor through one of the existing holes in the fan shroud. Another option is to place the thermometer between the radiator and the shroud. On some models, you may have to drill a 5 mm (3/16 in) hole in the fan shroud in order to insert the thermometer.
4. Cover the radiator while the thermometer is on position. Start the engine and operate the engine to 2000 RPM. This will induce a high engine temperature.
5. Observe the thermometer reading when the clutch engages. The temperature will become high enough to allow the fan clutch to engage after 5 to 10 minutes. This is indicated by an increase or roar in the fan air noise level. The thermometer reading also drops approximately 3-10°C (5-15°F).

Replace the unit if the clutch does not engage between 65-90°C (150-195°F). Ensure that the fan blade clutch disengaged at the start of the test.

Replace the unit under the following conditions:

•	There is no defined increase in fan noise.

•	No temperature drop is observed.

•	The fan noise level was constantly high from the start of the test to 88°C (190°F).

•	Do not continue the test past a thermometer reading of 88°C (190°F) in order to prevent engine overheating.

6. When the clutch engages, remove the radiator grille in order to assist in engine cooling. Run the engine at approximately 1500 RPM.
7. The fan clutch should disengage after a few minutes. The disengagement is indicated by a reduction in fan speed and roar. Replace the fan blade clutch if the fan blade clutch fails to function as described.