NO.12 NOISE WHILE OPERATING A/C SYSTEM

12	Noise while operating A/C system
DESCRIPTION	• Noise from magnetic clutch, A/C compressor, hose or refrigerant line.
POSSIBLE CAUSE	• Magnetic clutch operation noise • A/C compressor operation noise • A/C compressor slippage noise • Hose or refrigerant line interference noise


STEP	INSPECTION		ACTION
1	INSPECT A/C COMPRESSOR SLIPPAGE NOISE • Is there a squeaking or whirling sound (A/C compressor slippage noise)?	Yes	Go to Step 9.
1		No	Go to next step.
2	INSPECT A/C COMPRESSOR INTERFERENCE NOISE • Is there a rattling or vibrating sound (interference noise)?	Yes	Go to Step 12.
2		No	Go to next step.
3	INSPECT MAGNETIC CLUTCH OPERATION NOISE • Is there clicking sound (magnetic clutch operation noise)?	Yes	Adjust clearance between magnetic clutch pressure plate and A/C compressor pulley, then go to Step 13.
3		No	Go to next step.
4	INSPECT A/C COMPRESSOR NOISE TIME • Is noise heard continuously for more than 3 seconds after A/C compressor comes on?	Yes	Go to next step.
4		No	Condition is normal. (Noise normally occurs for 2-3 seconds immediately after A/C compressor turns on.)
5	INSPECT IDLE SPEED • Inspect idle speed. - L3: (See IDLE SPEED INSPECTION [L3]) - MZR-CD (RF-Turbo) (See IDLE SPEED INSPECTION [MZR-CD (RF Turbo)]) • Is it okay?	Yes	Adjust idle speed, then go to Step 13.
5		No	Go to next step.
6	VERIFY WHETHER MALFUNCTION IS IN COMPRESSOR OIL OR A/C COMPRESSOR • Drain compressor oil. • Is it contaminated with metal particles?	Yes	Replace A/C compressor, then go to Step 13.
6		No	Go to next step.
7	VERIFY WHETHER MALFUNCTION IS IN ENTIRE A/C SYSTEM OR A/C COMPRESOR AND CONDENSER • Is compressor oil whitish and mixed with water?	Yes	Replace entire A/C system (excluding heater), then go to Step 13.
7		No	Go to next step.
8	INSPECT COMPRESSOR OIL • Is compressor oil darker than normal and contaminated with aluminum chips?	Yes	Replace A/C compressor and condenser, then go to Step 13. (Since A/C compressor may be worn and receiver/drier may be clogged, replacement of condenser is necessary.)
8		No	Condition is normal. Recheck malfunction symptoms.
9	INSPECT DRIVE BELT • Inspect drive belt. - L3: (See DRIVE BELT INSPECTION [L3]) - MZR-CD (RF-Turbo) (See DRIVE BELT INSPECTION [MZR-CD (RF Turbo)]) • Is it okay?	Yes	Go to next step.
9		No	Replace drive belt, then go to Step 13.
10	INSPECT DRIVE BELT CONDITION • Is drive belt worn? • Does it have foreign material imbedded in it, or have oil on it?	Yes	Remove obstruction, remove oil, or replace drive belt, then go to Step 13.
10		No	Go to next step.
11	INSPECT MAGNETIC CLUTCH • Inspect magnetic clutch. (See MAGNETIC CLUTCH INSPECTION.) • Is it okay?	Yes	Replace A/C compressor (excluding pressure plate, A/C compressor pulley, and stator), then go to Step 13.
11		No	Replace magnetic clutch, then go to Step 13.
12	INSPECT A/C COMPRESSOR NOISE • Is noise coming from A/C compressor?	Yes	Visually inspect A/C compressor, replace appropriate parts if necessary, then go to next step.
12		No	If noise is coming from refrigerant lines, repair any detached or missing clips, tighten loose bolts, then go to next step.
13	VERIFY THAT MALFUNCTION SYMPTOM OCCURS AFTER REPAIR • Has A/C compressor noise stopped?	Yes	Troubleshooting completed. Explain repairs to customer.
13		No	Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.