K 1500 Yukon 4WD V8-4.8L VIN V (2003)
If after replacing the drive belt(s) and completing the diagnostic table, the rumbling is only heard with the drive belt(s) installed, there might be an
accessory drive component failure. Varying the load on the accessory drive component(s) may aid in identifying which component is causing the
rumbling noise.
Drive Belt Rumbling Diagnosis
Test Description
The number(s) below refer to the step(s) in the diagnostic table.
2. This test is to verify that the symptom is present during diagnosing. Other vehicle components may cause a similar symptom.
3. This test is to verify that the drive belt(s) is causing the rumbling. Rumbling may be confused with an internal engine noise due to the similarity in
the description. Remove only one drive belt at a time if the vehicle has multiple drive belts. Operate the engine for a few seconds, this will verify if
the rumbling noise is related to the drive belt(s) or not. With the drive belt(s) removed the water pump will not operate and the engine may
overheat. Also Diagnostic Trouble Codes (DTCs) may set when the engine is operated with the drive belt(s) removed.
4. Inspect the drive belt(s) to ensure that the drive belt(s) is not the cause of the noise. Small cracks across the ribs of the drive belt(s) will not cause
the noise. Belt separation is identified by the plys of the belt separating, this may be seen at the edge of the belt or felt as a lump in the belt.
5. Small amounts of pilling is a normal condition and acceptable. When the pilling is severe the drive belt(s) does not have a smooth surface for
proper operation.
Drive Belt Squeal
Drive Belt Squeal Diagnosis
Diagnostic Aids
A loose or improper installation of a body, or suspension component, or other item(s) on the vehicle may cause the squeal noise.
If the squeal is intermittent, verify that it is not the accessory drive component(s) by varying their load(s), making sure they are operating to their
