Diagnostic Aids
The symptom may be intermittent due to moisture on the drive belts or the pulleys. It may be necessary to spray a small amount of water on the drive belts in order to duplicate the customers concern. If spraying water on the drive belts duplicates the symptom, cleaning the belt pulley may be the probable solution.
Loose or improper installation of a body component, a suspension component, or other items of the vehicle may cause a chirping noise.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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The noise may not be engine related. This step is to verify that the engine is making the noise. If the engine is not making the noise do not proceed further with this table.
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The noise may be an internal engine noise. Removing the drive belt and operating the engine for a brief period will verify if the noise is related to the drive belt. With the drive belts removed the water pump may not be operating and the engine may overheat. Also DTCs may set when the engine is operating with a drive belt removed.
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Inspect all drive belt and pulleys for pilling. Pilling are small balls, pills or strings in the drive belt grooves from the accumulation of rubber dust.
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Misalignment of the pulleys may be caused from improper mounting of the accessory drive component, incorrect installation of a pulley, a bent pulley or a bent pulley shaft. Test for a misaligned pulley using a straight edge in the pulley grooves across two or three pulleys. If a misaligned pulley is found refer to that accessory drive component for the proper repair procedure.
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Inspecting the fasteners can determine if a wrong bolt, nut , spacer, or washer was installed. Missing, loose, or wrong fasteners may cause pulley misalignment . Improper tightening of the fasteners may cause misalignment of the accessory component bracket.
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The inspection of the pulleys should include inspecting for any damage to the pulleys that would prevent the drive belt from not seating properly in all of the pulley grooves or on the smooth surface of a pulley.
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Replacing the drive belt when it is not damaged or there is not excessive pilling may only be a temporary repair.
Step | Action | Yes | No | ||||
|---|---|---|---|---|---|---|---|
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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: The following items are indications of chirping:
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1 | Did you review the Drive Belt Symptom operation and perform the necessary inspections? | Go to Step 2 | |||||
Verify that there is a chirping noise. Does the engine make the chirping noise? | Go to Step 3 | Go to Diagnostic Aids | |||||
Does the chirping noise still exist? | Go to Step 4 | ||||||
Inspect for severe pilling exceeding 1/3 of the belt groove depth. Does the belt grooves have pilling? | Go to Step 5 | Go to Step 6 | |||||
5 | Clean the drive belt pulleys with a suitable wire brush. Did you complete the repair? | Go to Step 15 | Go to Step 6 | ||||
Inspect for misalignment of the pulleys. Are any of the pulleys misaligned? | Go to Step 7 | Go to Step 8 | |||||
7 | Replace or repair any misaligned pulleys. Did you complete the repair? | Go to Step 15 | Go to Step 8 | ||||
8 | Inspect for bent or cracked brackets. Did you find any bent or cracked brackets? | Go to Step 9 | Go to Step 10 | ||||
9 | Replace any bent or cracked brackets. Did you complete the repair? | Go to Step 15 | Go to Step 10 | ||||
Inspect for improper, loose or missing fasteners. Did you find the condition? | Go to Step 11 | Go to Step 12 | |||||
11 | Tighten any loose fasteners. Replace any improper or missing fasteners. Refer to Fastener Tightening Specifications . Did you complete the repair? | Go to Step 15 | Go to Step 12 | ||||
Inspect for a bent pulley. Did you find the condition? | Go to Step 13 | Go to Step 14 | |||||
13 | Replace the bent pulley. Did you complete the repair? | Go to Step 15 | Go to Step 14 | ||||
Replace the drive belt. Refer to Drive Belt Replacement . Did you complete the repair? | Go to Step 15 | Go to Diagnostic Aids | |||||
15 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 | ||||
