Ranger 2WD L4-153 2.5L SOHC VIN C SFI (1998)
Fan Clutch: Testing and Inspection
Minimum Speed Fan Clutch Requirement Test
1. Use a suitable marker to mark the water pump pulley, one of the fan blade retaining bolts, and the crankshaft pulley.
2. Connect a tachometer to the engine.
3. Install a throttle adjusting tool.
4. Connect a digital photoelectric tachometer.
5. Start the engine and run it at approximately 1500 rpm until the normal operating temperature has been achieved.
WARNING: TO AVOID THE POSSIBILITY OF PERSONAL INJURY OR DAMAGE TO THE VEHICLE, DO NOT OPERATE THE
ENGINE UNTIL THE FAN BLADE HAS BEEN FIRST EXAMINED FOR POSSIBLE CRACKS AND SEPARATION.
6. Adjust the engine speed to 2307 rpm.
7. Adjust the strobe light to 3000 rpm and aim it at the water pump pulley. Adjust the engine speed until the light flash and the water pump pulley
mark are synchronized.
8. Aim the strobe light at the fan blade retaining bolts. Adjust the strobe light until the light flash is synchronized with the marked fan blade retaining
bolt (fan blade appears to stand still).
9. The fan blade speed must not be greater than 1500 rpm at 3000 water pump rpm.
10. Turn the engine OFF.
11. If the fan blade speed was greater than 1500 rpm, replace the fan clutch.
