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Noise Diagnosis - Air Conditioning (A/C) System

Noise Diagnosis - Air Conditioning (A/C) System


Step Action Yes No
DEFINITION: Noise originating from the A/C compressor, drive belt, or the A/C lines.

1

Were you sent here from Symptoms or another diagnostic table?

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Go to Symptoms - HVAC Systems - Automatic

2


1. A/C system noises can be generally categorized into 3 areas:

• Screeching, squealing, chirping noises

• Moaning noises

• Vibration/rattle noises

2. Start the engine.

3. Ensure that the A/C is ON.


Is a screeching, squealing noise heard when the A/C is engaged?

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3

With the engine OFF, inspect the drive belt for excessive wear. Refer to the appropriate procedure:


• Drive Belt Falls Off and Excessive Wear Diagnosis for the 2.0L engine

• Drive Belt Falls Off and Excessive Wear Diagnosis for the 2.0L (Diesel) engine


Is the drive belt excessively worn?

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4

Check the drive belt tension. Refer to the appropriate procedure:


• Drive Belt Tensioner Diagnosis for the 2.0L engine

• Drive Belt Tensioner Diagnosis for the 2.0L (Diesel) engine

• Drive Belt Tensioner Diagnosis for the 2.8L engine


Is the drive belt tension correct?

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5

Inspect the drive belt for excessive oil coverage.

Is the drive belt covered with oil?

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6


1. Start the engine.

2. Ensure that the A/C is ON.

3. Inspect the compressor and the clutch.


Is the A/C compressor locked up?

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7

Is the A/C compressor clutch slipping?

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8

Refer to Moving Parts and Hot Surfaces Warning .

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

Is the compressor causing an abnormal noise?

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9

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

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10

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?

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11


1. Idle 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 a component of the A/C system touching another component.


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

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12

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

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13

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

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14


1. Idle the engine in PARK with the A/C compressor clutch engaged.

2. Using a stethoscope, move around the entire A/C system testing for any abnormal noises caused by a component.


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

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15

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

Is the A/C system properly charged.

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16

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

Is the abnormal compressor noise still present?

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17

Repair the oil leak. Refer to the appropriate procedure:


• Oil Leak Diagnosis for the 2.0L engine

• Oil Leak Diagnosis for the 2.0L (Diesel) engine

• Oil Leak Diagnosis for the 2.8L, 3.0L, 3.2L or 3.6L engine


Is the repair complete?

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18

Replace the drive belt. Refer to the appropriate procedure:


• Drive Belt Replacement for the 2.0L engine

• Drive Belt Replacement for the 2.0L (diesel) engine

• Drive Belt Replacement for the 2.8L, 3.0L, 3.2L or 3.6L engine


Is the replacement complete?

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19

Replace the drive belt tensioner. Refer to the appropriate procedure:


• Drive Belt Tensioner Replacement for the 2.0L engine

• Drive Belt Tensioner Replacement for the 2.0L (diesel) engine

• Drive Belt Tensioner Replacement for the 2.8L, 3.0L, 3.2L or 3.6L engine


Is the replacement complete?

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20

Repair or replace the A/C compressor mounting component.

Is the repair complete?

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21

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

Is the repair complete?

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22

Correctly route or insulate the A/C component.

Is the repair complete?

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23

Replace the A/C compressor clutch.

Is the repair complete

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24

Replace the A/C compressor. Refer to Air Conditioning Compressor Replacement (LDK/A20NHT) Air Conditioning Compressor Replacement (LBS/A20DTH) Air Conditioning Compressor Replacement (LAU/A28NER) .

Is the repair complete?

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25

The concern may be caused by an engine related component. Refer to Vibration Analysis - Engine .

Did you find and correct the condition?

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26

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

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