Silverado 3500 2WD V8-6.6L DSL Turbo VIN 2 (2004)
Steps 10 - 11
The numbers below refer to the steps in the diagnostic table.
2. This test is to verify that the vibration is present during diagnosing. Other vehicle components may cause a similar symptom such as the exhaust
system, or the drivetrain.
3. This test is to verify that the drive belt or accessory drive components may be causing the vibration. Remove the drive belt and operate the engine
for a few seconds, this will verify if the vibration is related to the drive belt or not. With the drive belt 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 removed.
4. The drive belt may cause a vibration. While the drive belt is removed this is the best time to inspect the condition of the drive belt.
6. Inspection of the fasteners can eliminate the possibility that a incorrect 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 smooth operation. Inspect for a bent fan shaft or bent mounting flange.
9. Inspect the water pump drive shaft for being bent. Also inspect the water pump bearings for smooth operation 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 an extra strain on that accessory drive component causing it to
vibrate.
Drive Belt Whine
Drive Belt Whine Diagnosis
Diagnostic Aids
The drive belt will not cause the whine.
If the whine is intermittent, verify that it is not the accessory drive components by varying their loads, making sure they are operating to their
maximum capacity. An overcharged air conditioning (A/C) system, a power steering system restriction or the incorrect fluid, or a failing generator are
suggested items to inspect.
Test Description
Steps 1 - 2
