Skylark V6-3100 3.1L VIN M SFI (1996)
Fan Clutch: Testing and Inspection
Fig. 4 Bi-Metal Spring Disengagement
Do not operate the engine until the fan has been checked for possible cracks and separations.
Run the engine at a fast idle speed (1000 RPM) until normal operating temperature is reached. This process can be expedited by blocking off the front
of the radiator with a suitable piece of cardboard. Regardless of temperature, the unit must be operated for at least five minutes before being tested.
Stop the engine and, using a glove or a cloth, immediately check the effort required to turn the fan. If considerable effort is required, it can be assumed
that the coupling is operating satisfactorily. If very little effort is required to turn the fan, it is an indication that the coupling is not operating properly
and should be replaced.
If the clutch fan is the coiled bi-metal spring type, it may be tested while the vehicle is being driven. To check, disconnect the bi-metal spring, Fig. 4 ,
and rotate the spring 90° counterclockwise. This disables the temperature controlled free wheeling feature and the clutch performs like a conventional
fan. If this cures the overheating condition, replace the fan clutch.
