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NO.12 NOISE WHILE OPERATING A/C SYSTEM

BME070300000W14

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

Diagnostic procedure

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.
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.
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.
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.
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.
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.
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.
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.)
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.
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.
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.
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.
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.
No | Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.