For 1990-2009 cars

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 HVAC Symptoms or another diagnostic table? | Go to Step 2 | Go to Diagnostic System Check - Vehicle.
2 | Inspect and if necessary rectify any faults with the accessory drive belt and drive belt tensioner. | Go to Step 3 |
3 | Run the engine and check for possible compressor noise. Does the noise last longer than 30 seconds? | Go to Step 5 | Go to Step 4
4 |

• | Allow the engine to run for a few minutes.

• | Stop engine and let it rest for a minute.

• | Restart engine.

Is any noise detected using this procedure?

Go to Step 6

It is normal to observe a liquid sludging condition. This may occur after extended system shut down at warmer ambient temperatures, followed by an overnight ambient temperature drop

5 | Check if the system has a low refrigerant charge. Is there enough system gas? | Go to Step 7 | Go to Step 8
6 | Check if the thermostatic expansion (TX) valve is stuck closed or open. Is the TX valve stuck? | Carry out TX valve diagnosis. Refer to Air Conditioning Evaporator Thermal Expansion Valve Replacement. | Go to Step 7
7 | Check for any loose compressor bolt and/or A/C plumbing contacting the bodywork. Is there any A/C plumbing contacting the bodywork or mounting bolts loose? | Tighten bolts and/or relocate plumbing | Go to Step 8
8 |

1. Recover refrigerant and replace compressor.
2. Recharge the system

Are the gas pressures within specification?

System checks complete

Go to Step 1