Diagnostic Aids
The chirping noise may be intermittent due to moisture on the drive belts or the accessory drive pulleys. in order to duplicate the customer concern, It may be necessary to spray a small amount of water onto the drive belts. If spraying water on the drive belts duplicates the symptom, cleaning the accessory drive pulleys may be the most probable solution.
A loose or incorrect installation of a body or suspension component, or other items on the vehicle may cause the chirping noise.
Test Description
The numbers below refer to the steps in the diagnostic table.
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The chirping 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 in this table.
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The noise may be an internal engine noise. Remove the drive belts and operate the engine for a few seconds, this will verify if the chirping noise is related to the drive belts or not. With the drive belts 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 belts removed.
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Inspect the drive belts for signs of pilling. Pilling is the small balls, pills, or strings in the drive belt grooves caused by the accumulation of rubber dust.
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Misalignment of the accessory drive pulleys may be caused from incorrect mounting or incorrect installation of an accessory drive component, or the pulley may be bent inward or outward from a previous repair. Test for a misaligned pulley using a straight edge in the pulley grooves across 2 or 3 pulleys. If a misaligned pulley is found refer to that accessory drive component for the correct removal and installation procedure for that pulley.
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Inspection of the fasteners can address the possibility that a incorrect bolt, nut, spacer, or washer was installed.
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Inspection the accessory drive pulleys should include inspecting for bends, dents or other damage to the pulleys that May prevent the drive belts from seating correctly in the pulley grooves or on the smooth surface of a pulley when the back side of the drive belt is used to drive the pulley.
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Replacing the drive belts when it is not damaged or there is not above acceptable pilling will only be a temporary repair.
Step | Action | Yes | No | ||||
|---|---|---|---|---|---|---|---|
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Notice: Refer to Belt Dressing Notice in the Preface section. DEFINITION: The following items are indications of chirping:
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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 chirping noise. Does the engine make the chirping noise? | Go to Step 3 | Go to Diagnostic Aids | ||||
3 |
Does the chirping noise still exist? | Go to Engine Noise on Start-Up, but Only Lasting a Few Seconds or Upper Engine Noise, Regardless of Engine Speed or Lower Engine Noise, Regardless of Engine Speed. | Go to Step 4 | ||||
4 | Inspect for extreme drive belt pilling exceeding 1/3 of the drive belt groove depth. Do the drive belt grooves have pilling? | Go to Step 5 | Go to Step 6 | ||||
5 | Clean the accessory drive pulleys with a suitable wire brush. Were the accessory drive pulleys cleaned? | Go to Step 14 | -- | ||||
6 | Inspect for a misaligned accessory drive pulleys. Is there a misaligned accessory drive pulleys? | Go to Step 7 | Go to Step 8 | ||||
7 | Replace and/or repair the misaligned accessory drive pulleys. Refer to Power Steering Pump Pulley Replacement. Refer to Drive Belt Idler Pulley Replacement or Drive Belt Tensioner Replacement - Accessory or Drive Belt Tensioner Replacement - Air Conditioning. Were the misaligned accessory drive pulleys replaced and/or repaired? | Go to Step 15 | -- | ||||
8 | Inspect for a bent or cracked accessory drive brackets. Did you find any bent or cracked accessory drive brackets? | Go to Step 9 | Go to Step 10 | ||||
9 | Replace the bent and/or cracked accessory drive brackets. Refer to Compressor Mounting Bracket Replacement. Refer to Generator Bracket Replacement. Was the bent and/or cracked accessory drive brackets replaced? | Go to Step 15 | -- | ||||
10 | Inspect for incorrect, loose, and/or missing fasteners. Were there any incorrect, loose, and/or missing fasteners found? | Go to Step 11 | Go to Step 12 | ||||
11 |
Were the fasteners replaced and/or tightened? | Go to Step 15 | -- | ||||
12 | Inspect for a bent accessory drive pulleys. Refer to Power Steering Pump Pulley Replacement. Refer also to Drive Belt Idler Pulley Replacement or Drive Belt Tensioner Replacement - Accessory or Drive Belt Tensioner Replacement - Air Conditioning. Was a bent accessory drive pulleys found? | Go to Step 13 | Go to Step 14 | ||||
13 | Replace the bent accessory drive pulleys. Refer to Power Steering Pump Pulley Replacement. Refer also to Drive Belt Idler Pulley Replacement or Drive Belt Tensioner Replacement - Accessory or Drive Belt Tensioner Replacement - Air Conditioning. Was the bent accessory drive pulleys replaced? | Go to Step 15 | -- | ||||
14 | Replace the drive belts. Refer to Drive Belt Replacement - Accessory or Air Conditioning Compressor Belt Replacement. Was the drive belts replaced? | Go to Step 15 | -- | ||||
15 |
Does the chirping noise still exist? | Go to Step 3 | System OK | ||||
