Drive Belt Vibration

Drive Belt Vibration Diagnosis





Drive Belt Vibration Diagnosis

Diagnostic Aids
The accessory drive components can have an affect on engine vibration. Some of the causes of component vibration can be that the A/C system is over charged, the power steering system is restricted or has incorrect fluid, or there is an extra load on the generator. To help identify an intermittent or an improper condition, vary the loads on the accessory drive components.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. This test is to verify that the symptom is present during diagnosing. Other vehicle components, such as the exhaust system or the drivetrain, may cause a similar symptom.
3. This test is to verify that the drive belt or accessory drive components may be causing the vibration. With the drive belt removed the water pump may not be operating and the engine may overheat. Also DTCs may set when the engine is operating with the drive belt removed.
4. The drive belt may cause a vibration. The best time to inspect the condition of the drive belt is while it is removed from the vehicle.
6. Inspection of the fasteners can determine if a wrong bolt, nut, spacer, or washer was installed.
8. This step should only be performed if the fan is driven by the drive belt. Inspect the engine cooling fan for bent, twisted, loose, or cracked blades. Inspect the fan clutch for smoothness and ease of turning. Inspect for a bent fan shaft or bent mounting flange.
9. This step should only be performed if the water pump is driven by the drive belt. Inspect the water pump for a bent shaft. Also inspect the water pump bearings for smoothness and excessive play. Compare the water pump with a known good water pump.
10. Accessory drive component brackets that are bent, cracked, or loose may put extra strain on that accessory component causing it to vibrate.