Diagnostic information
Drive belts themselves do not cause a whining noise. If the noise is intermittent, inspect the accessory drive components by varying their loads and confirm that they are operating at peak performance. Excess refrigerant in the air conditioning system, a restricted power steering circuit, or a faulty alternator are likely the cause of accessory drive belt whining.
Description of the test
The item numbers below are the step numbers in the diagnostic chart.
- This noise can be caused by internal engine components. Removing the drive belt and letting the engine run for a while can confirm or deny that the noise is related to the drive belt.
- Bearing inspection should cover the following drive components of the units:
- drive belt tensioners;
- drive belt tension rollers;
- generator;
- power steering pump;
- air conditioning compressor.
To locate the faulty bearing, it may be necessary to install the drive belt and operate the accessory drive components individually, varying the loads; see the relevant sections for component inspection and repair procedures.
Diagnostic table
Definition: Accessory drive belt whine can be defined as a high-pitched, continuous sound that is most likely caused by a failed bearing on one of the accessory drive components.
| Step | Operation | Values | Yes | No |
| 1 |
Have you reviewed the information provided in the Symptoms section and performed the required checks?
|
-
|
Jump to operations 2
|
Go to item Symptoms
|
| 2 |
Confirm the customer complaint. Is there a howling noise?
|
-
|
Jump to operations 3
|
See diagnostic recommendations in this section
|
| 3 |
Is the whining sound still present?
|
-
|
The drive system of the units is in order.
Go to "Symptoms" and start diagnostics again
|
Jump to operations 4
|
| 4 |
Inspect accessory drive components for damage, bearing seizure, and general faults.
Have bearing damage/seizures and general faults in the accessory drive system been identified and corrected?
|
-
|
Jump to operations 5
|
See diagnostic recommendations in this section
|
| 5 |
Reinstall the accessory drive belt and operate the system to confirm completion of the repair.
Is the howling noise eliminated?
|
-
|
The drive system of the units is in order
|
Jump to "Symptoms" and restart the diagnostics
|
[The article is reprinted from the website «CHEVYMAN»]