Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Functional Check or the Diagnostic System Check? | -- | Go to Step 2 | Go to Functional Check in HVAC Systems - Manual or Diagnostic System Check Diagnostic System Check in HVAC Automatic | ||||||
2 |
Is an abnormal noise present? | -- | Go to Noise Diagnosis | Go to Step 3 | ||||||
3 |
Is the A/C clutch engaged and supplying cold air to the passenger compartment? | -- | Go to Step 4 | Go to HVAC Compressor Controls System Check in HVAC Systems - Manual | ||||||
4 | A/C system noises can be generally categorized into three areas:
Is a screech/squealing noise heard when the A/C clutch is engaged? | -- | Go to Step 5 | Go to Step 11 | ||||||
5 | Inspect the A/C compressor drive belt for excessive wear or oil coverage. Is the drive belt excessively worn or covered with oil? | -- | Go to Step 6 | Go to Step 7 | ||||||
6 |
Refer to Oil Leak Diagnosis in Engine Mechanical. Did you complete the repair? | -- | Go to Step 25 | -- | ||||||
7 | Is the A/C compressor clutch slipping or the compressor locked up? | -- | Go to Step 8 | Go to Step 9 | ||||||
8 |
Did you complete the repair? | -- | Go to Step 25 | -- | ||||||
9 |
Is the idler pulley and tensioner causing an abnormal noise? | -- | Go to Step 10 | Go to Step 11 | ||||||
10 | Replace the A/C compressor drive belt idler pulley or tensioner as necessary. Did you complete the repair? | -- | Go to Step 25 | -- | ||||||
11 | Does a moaning noise exist when the A/C clutch is engaged? | -- | Go to Step 12 | Go to Step 20 | ||||||
12 |
Important: A moaning/rumbling noise originating from the compressor could be caused by the system being less than 1/2 pound low on charge. The performance test may not detect the system being under charged less than 1/2 pound. Perform a system performance test to verify the A/C system is properly charged. Refer to System Performance Test Is the A/C system properly charged? | -- | Go to Step 14 | Go to Step 13 | ||||||
13 |
Does the moaning noise exist when the A/C clutch is engaged? | -- | Go to Step 14 | Go to Step 25 | ||||||
14 | Inspect the A/C compressor mounting, idler pulley, and tensioner for concerns using a stethoscope. Are any of these components loose, damaged or excessively worn? | -- | Go to Step 15 | Go to Step 16 | ||||||
15 | Repair or replace the A/C compressor mounting, idler pulley or tensioner/tensioner pulley as needed. Did you complete the repair? | -- | Go to Step 25 | -- | ||||||
16 |
Are any of the A/C components grounding out and causing a noise? | -- | Go to Step 17 | Go to Step 18 | ||||||
17 | Repair or replace the component which is causing the moaning concern as needed. Did you complete the repair? | -- | Go to Step 25 | -- | ||||||
18 | Does the concern go away with the A/C clutch disengaged and the engine idling in PARK? | -- | Go to Step 19 | Go to Diagnostic Information and Procedures in Vibration Diagnosis and Correction | ||||||
19 | Replace the A/C Compressor. Refer to Air Conditioning Compressor Replacement . Did you complete the repair? | -- | Go to Step 25 | -- | ||||||
20 | Does a vibration or rattle noise exist when the A/C clutch is engaged? | -- | Go to Step 21 | System OK | ||||||
21 | Inspect the A/C compressor mounting, idler pulley, and tensioner for concerns using a stethoscope. Are any of these components loose, damaged or excessively worn? | -- | Go to Step 15 | Go to Step 22 | ||||||
22 |
Are any of the A/C components causing an abnormal noise? | -- | Go to Step 23 | Go to Step 24 | ||||||
23 | Repair or replace the component which is causing the vibration/rattle concern as needed. Did you complete the repair? | -- | Go to Step 25 | -- | ||||||
24 | Is the vibration/rattle coming from the A/C compressor internally? | -- | Go to Step 19 | Go to Diagnostic Information and Procedures in Vibration Diagnosis and Correction | ||||||
25 | Operate the system in order to verify the repair. Did you find and correct the condition? | -- | System OK | Go to Step 2 |
