Engine Overheating

1. In order to ensure complete fan blade clutch disengagement, begin testing with a cool engine.
2. With the engine OFF, spin the fan blade clutch assembly.
^ If the fan blade clutch assembly free wheels with no drag, (revolves more than 5 times when spun by hand), replace the fan blade clutch.
^ If the clutch performs properly with a slight drag, go to step 3.
^ Spin the fan blade clutch by holding the small hub with one hand and rotate the aluminum housing in a clockwise/counterclockwise motion. If the spinning causes the clutch to free wheel, consider this operation normal and the fan blade clutch should not be replaced.
3. Position a thermometer between the fan blades and the radiator by doing the following:
^ Insert the thermometer sensor through one of the existing holes in the fan shroud.
^ On some models, you may have to drill a 5 mm (3/16 inch) hole in the fan shroud in order to insert the thermometer.

Important: Check for adequate clearance between the fan blades and the thermometer sensor before starting the engine.

4. With the thermometer in position, do the following steps:
4.1. Sufficiently cover the radiator grille in order to induce a high engine temperature.
4.2. Start the engine.
4.3. Turn on the A/C.
4.4. Operate the engine at 2000 RPM.
5. Check the thermometer reading when the clutch engages. Allow about 5 to 10 minutes for the temperature to become high enough to engage the fan blade clutch. This will be indicated by an increase, or roar, in fan air noise and by a drop in the thermometer reading of about 3 - 10°C (5 - 15°F).
^ If the clutch did not engage between 65 - 90°C (150 - 195°F), replace the assembly. Make sure that the fan blade clutch was disengaged at the beginning of the test.
^ If you observed no sharp increase in fan noise or temperature drop, and the fan noise level was constantly high from the start of the test to 88°C (190°F), replace the assembly. Do not continue this test past a thermometer reading of 88°C (190°F) in order to prevent engine overheating.
6. When the clutch engages, do the following steps:
6.1. Remove the radiator grille cover.
6.2. Turn off the A/C in order to assist in Cooling System.
6.3. Operate the engine at about 1500 RPM.
7. After several minutes, the fan blade clutch should disengage as indicated by a reduction in fan speed and roar. If the fan blade clutch fails to function as described, replace the fan blade clutch.