Circuit/System Testing

Start the engine. Verify the noise can be heard. Compare the concern to a similar vehicle.
Perform a charging system test. Verify that the generator is charging properly.
Inspect the generator, generator mounting, wiring harness, heater hoses, A/C lines, or other accessory equipment that may be misrouted or be the cause of noise being transmitted into the passenger compartment.
Ignition OFF, remove the engine drive belt.
Verify the generator, A/C compressor, water pump pulley, power steering pump, idler pulley, and tensioner pulley spin freely.
- If any of the pulleys do not spin freely
  Replace the affected component.
- If all belt driven components spin freely
Start the engine. Operate the engine for no longer than 30-40 seconds.
Verify that the noise goes away.
- If the noise is still present
  The generator is not the cause of the noise. Refer to Symptoms - Engine Mechanical .
- If noise is no longer present
Inspect for worn accessory drive components or abnormalities such as severe cracking, bumps, or missing areas in the accessory drive belt and/or misalignment of system components