DEFINITION: Noise originating from the A/C compressor, drive belt or the A/C lines.

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Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

1. A/C system noises can be generally categorized into three areas:

•	Screeching, squealing, chirping noises

•	Moaning noises

•	Vibration/rattle noises

2. Start the engine.
3. Ensure that the A/C is ON.

Do you hear a screeching, squealing noise when you engage the A/C?

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With the engine OFF, inspect the drive belt for excessive wear. Refer to the following procedures:

Is the drive belt excessively worn?

Go to Step 18

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Inspect the drive belt tension. Refer to the following procedures:

Is the drive belt tension correct?

Go to Step 19

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Inspect the drive belt for excessive oil coverage.

Is the drive belt covered with oil?

Go to Step 17

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1. Start the engine.
2. Ensure that the A/C is ON.
3. Inspect the compressor and the clutch.

Is the compressor locked up?

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Is the A/C compressor clutch slipping?

Go to Step 23

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Using a stethoscope, listen to the A/C compressor for any abnormal noises.

Is the compressor causing an abnormal noise?

Go to Step 15

Go to Step 10

Does a moaning noise exist when the A/C clutch is engaged?

Go to Step 10

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Listen to the A/C compressor components and mounting for noise concerns using a stethoscope.

Are any of these components loose, damaged or excessively worn?

Go to Step 20

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1. Start the engine.
2. Engage the A/C compressor clutch.
3. Using a stethoscope, move around the entire refrigerant plumbing system, listening for any abnormal noises caused by component ground-out.

Are any of the A/C components grounding out and causing a noise?

Go to Step 22

Go to Step 13

Does a vibration or rattle noise exist when the A/C clutch is engaged?

Go to Step 13

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Does the noise stop when the A/C clutch is disengaged?

Go to Step 15

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1. Idle the engine in PARK with the A/C compressor clutch engaged.
2. Using a stethoscope, move around the entire A/C system listening for any abnormal noises caused by a component.

Do any of the A/C components cause an abnormal noise?

Go to Step 21

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Verify that the A/C system is properly charged. Refer to Refrigerant System Capacities .

Is the A/C system properly charged?

Go to Step 24

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Recharge the A/C system to specification. Refer to Refrigerant Recovery and Recharging .

Is the abnormal compressor noise still present?

Go to Step 24

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Repair the oil leak. Refer to the appropriate repair procedure in Engine Mechanical.

Is the repair complete?

Go to Step 25

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Replace the drive belt. Refer to the following procedures:

Is the replacement complete?

Go to Step 25

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Replace the drive belt tensioner. Refer to the following procedures:

Is the replacement complete?

Go to Step 25

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Repair or replace the A/C compressor mounting component.

Is the repair complete?

Go to Step 25

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Repair or replace the component which is causing the moaning concern as needed.

Is the repair complete?

Go to Step 25

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Correctly route or insulate the A/C component.

Is the repair complete?

Go to Step 25

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Replace the A/C compressor. Refer to Air Conditioning Compressor Replacement .

Is the replacement complete?

Go to Step 25

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The concern may be caused by an engine related component. Refer to the following procedures:

Did you find and correct the condition?

Go to Step 25

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Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2