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? | Go to Step 2 | Go to Symptoms - HVAC Systems - Automatic in HVAC Systems - Automatic | ||||||
2 |
Do you hear a screeching, squealing noise when you engage the A/C? | Go to Step 3 | Go to Step 9 | ||||||
3 | With the engine OFF, inspect the A/C drive belt for excessive wear. Refer to Drive Belt Excessive Wear Diagnosis in Engine Mechanical - 6.0L. Is the drive belt excessively worn? | Go to Step 18 | Go to Step 4 | ||||||
4 | Inspect the A/C drive belt tensioner. Refer to Drive Belt Tensioner Diagnosis in Engine Mechanical - 6.0L. Is the drive belt tension correct? | Go to Step 5 | Go to Step 19 | ||||||
5 | Inspect the drive belt for excessive oil coverage. Is the drive belt covered with oil? | Go to Step 17 | Go to Step 6 | ||||||
6 |
Is the A/C compressor locked up? | Go to Step 23 | Go to Step 7 | ||||||
7 | Is the A/C compressor clutch slipping? | Go to Step 23 | Go to Step 8 | ||||||
8 |
Caution: Avoid contact with moving parts and hot surfaces while working around a running engine in order to prevent physical injury. 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 | ||||||
9 | Does a moaning noise exist when the A/C clutch is engaged? | Go to Step 10 | Go to Step 12 | ||||||
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? | Go to Step 20 | Go to Step 11 | ||||||
11 |
Are any of the A/C components grounding out and causing a vibration noise? | Go to Step 22 | Go to Step 13 | ||||||
12 | Does a vibration or rattle noise exist when the A/C clutch is engaged? | Go to Step 13 | Go to Step 14 | ||||||
13 | Does the noise stop when the A/C clutch is disengaged? | Go to Step 15 | Go to Step 24 | ||||||
14 |
Do any of the A/C components cause an abnormal noise? | Go to Step 21 | Go to Step 24 | ||||||
15 | 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 | Go to Step 16 | ||||||
16 | Recharge the A/C system to specification. Refer to Refrigerant Recovery and Recharging . Is the abnormal compressor noise still present? | Go to Step 23 | Go to Step 25 | ||||||
17 | Repair the oil leak. Refer to the appropriate repair procedure in Engine Mechanical - 6.0L. Is the repair complete? | Go to Step 25 | -- | ||||||
18 | Replace the A/C drive belt. Refer to Air Conditioning Compressor Belt Replacement in Engine Mechanical - 6.0L. Is the replacement complete? | Go to Step 25 | -- | ||||||
19 | Replace the A/C drive belt tensioner. Refer to Drive Belt Tensioner Replacement - Air Conditioning in Engine Mechanical - 6.0L. Is the replacement complete? | Go to Step 25 | -- | ||||||
20 | Repair or replace the A/C compressor mounting component. Is the repair complete? | Go to Step 25 | -- | ||||||
21 | Repair or replace the component which is causing the moaning concern as needed. Is the repair complete? | Go to Step 25 | -- | ||||||
22 | Correctly route or insulate the A/C component. Is the repair complete? | Go to Step 25 | -- | ||||||
23 | Replace the A/C compressor. Refer to Air Conditioning Compressor Replacement . Is the replacement complete? | Go to Step 25 | -- | ||||||
24 | The concern may be caused by an engine related component. Refer to Vibration Analysis - Engine in Vibration Diagnosis and Correction. Did you find and correct the condition? | Go to Step 25 | -- | ||||||
25 | Operate the system in order to verify the repair. Did you find and correct the condition? | System OK | Go to Step 2 | ||||||
