AIR CONDITIONER — A/C compressor noise troubleshooting
G-61flowchartInspection
Because the A/C compressor is a rotary vane type, an irregular noise may be heard when the refrigerant is charged from the low-pressure side or after replacing components without adjusting the amount of compressor oil. Noise is produced when the vanes are not properly pressed against the inner wall of the rotor housing.
A/C compressor noise troubleshooting
1
Noise heard with magnetic clutch on.
Noise originates from inside A/C compressor at excessively low idle.
Noise originates from inside A/C compressor at excessively low idle.
Imprecise setting of idle
Adjust idle speed
Noise originates from inside A/C compressor during refrigerant charge.
Noise originates from inside A/C compressor during refrigerant charge.
No charge in pressures (discharge and suction side)
Procedure 2
Noise originates from inside A/C compressor after refrigerant system parts are replaced.
Noise originates from inside A/C compressor after refrigerant system parts are replaced.
Insufficient compressor oil
Procedure 3
A brief noise originates from inside A/C compressor when it starts operation.
A brief noise originates from inside A/C compressor when it starts operation.
Normal
2
Noise originates from inside A/C compressor at idle. Noise stops when speed is increased.
3
Compressor oil or refrigerant leakage
4
Procedure 1
Procedure 1
Check the entire refrigerant system for compressor oil and refrigerant leaks. If leakage is found, repair or replace as necessary.
Procedure 2
Run the engine at a constant 3000—4000 rpm; then alternately switch the A/C compressor on and off (turn the A/C switch on and off). If the noise remains, turn the ignition switch to OFF for 1—2 minutes. Start the engine again, hold its speed at 3000—4000 rpm, and alternately switch the A/C compressor on and off (turn the A/C switch on and off).
Procedure 3
After replacing parts, add compressor oil as shown in the following table.
Procedure 3 — Oil supplement
Condenser
Oil supplement30 ml {30 cc, 1.0 fl oz}
Cooling unit
Oil supplement60 ml {60 cc, 2.0 fl oz}
Piping hose/pipe
Oil supplement5 ml {5 cc, 0.2 fl oz}
Receiver/drier
Oil supplement10 ml {10 cc, 0.3 fl oz}