GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Kodiak C-Series Motorhome (Cutaway) C4/C5 🢒 Engine 🢒 Engine Controls - 6.6L (LLY) 🢒 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

The numbers below refer to the steps in the diagnostic table.

  1. This test is to verify that the whine is being caused by the accessory drive components. Remove the drive belt and operate the engine for a few seconds, this will verify if the whining noise is related to the accessory drive component. With the drive belt removed the cooling fan 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.

    2.

  2. The inspection should include checking the drive belt tensioner and the drive belt idler pulley bearings. The drive belt may have to be installed and the accessory drive components operated separately by varying their loads. Refer to the suspected accessory drive component for the proper removal and replacement procedure.

Step

Action

Yes

No

Notice: Do not use belt dressing on the drive belt. Belt dressing causes the breakdown of the composition of the drive belt. Failure to follow this recommendation will damage the drive belt.

DEFINITION: A high pitched continuous noise that may be caused by an accessory drive component failed bearing.

1

Did you review the Symptoms - Engine Mechanical diagnostic information, and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Engine Mechanical

2

Verify that there is a whining noise.

Does the engine make the whine noise?

Go to Step 3

Go to Diagnostic Aids

3

  1. Remove the drive belt. Refer to Drive Belt Replacement .
  2. Operate the engine for no longer than 30 to 40 seconds.

Does the whining noise still exist?

Go to Engine Noise on Start-Up, but Only Lasting a Few Seconds

Go to Step 4

4

Inspect for a failed accessory drive component bearing.

Did you find and correct the condition?

Go to Step 5

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5
  1. Clear any codes.
  2. Run the engine in order to verify the repair.

Does the whining still exist?

--

System OK