NO.8 NOISE WHILE OPERATING A/C SYSTEM. [5R55S]
id070304812700
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8
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Noise while operating A/C system
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DESCRIPTION
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• Noise from magnetic clutch, A/C compressor, hose or refrigerant line.
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POSSIBLE CAUSE
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• Magnetic clutch operating noise (Step 3)
• A/C compressor operation noise (Step 4—8)
• A/C compressor slippage noise (Step 9—11)
• Hose or refrigerant line interference noise (Step 12)
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Diagnostic procedure
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STEP |
INSPECTION |
ACTION |
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1
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INSPECT A/C COMPRESSOR SLIPPAGE NOISE
• Is there squeaking or whirling sound (A/C compressor slippage noise)?
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Yes
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Go to Step 9.
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No
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Go to the next step.
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2
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INSPECT A/C COMPRESSOR INTERFERENCE NOISE
• Is there a rattle or vibrating sound (interference noise)?
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Yes
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Go to Step 12.
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No
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Go to the next step.
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3
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INSPECT MAGNETIC CLUTCH OPERATION NOISE
• Is there a clicking sound (magnetic clutch operation noise)?
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Yes
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Adjust clearance between magnetic clutch pressure plate and A/C compressor pulley, the go to Step 13.
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No
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Go to the next step.
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4
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INSPECT A/C COMPRESSOR NOISE TIME
• Is noise heard continuously for more than 3 seconds after A/C compressor comes on?
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Yes
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Go to the next step.
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No
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Condition is normal. (Noise normally occurs for 2—3 seconds immediately after A/C compressor turns on.)
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5
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INSPECR IDLE SPEED
• Inspect idle speed.
• Is it okay?
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Yes
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Go to the next step.
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No
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Inspect and repair related parts, according to inspection results.
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6
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CHECK TO SEE WHETHER MALFUNCTION IS IN A/C COMPRESSOR OR ELSEWHERE
• Drain compressor oil.
• Is it contaminated with metal particles?
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Yes
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Go to the next step.
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No
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Replace A/C compressor, then go to Step 13.
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7
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CHECK TO SEE WHETHER MALFUNCTION IS IN A/C SYSTEM OR ELSEWHERE
• Is compressor oil whitish and mixed with water?
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Yes
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Replace entire A/C system (excluding heater), then go to Step 13.
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No
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Go to the next step.
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8
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INSPECT COMPRESSOR OIL
• Is compressor oil darker than normal and contaminated with aluminum chips?
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Yes
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Replace A/C compressor and receiver/drier, then go to Step 13.
(Since A/C compressor may be worn and receiver/drier may be clogged, replacement of receiver/drier is necessary.)
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No
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Condition is normal.
Recheck malfunction symptoms.
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9
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INSPECT DRIVE BELT
• Inspect drive belt.
• Is it okay?
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Yes
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Go to the next step.
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No
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Adjust or replace drive belt, then go to Step 13.
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10
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INSPECT DRIVE BELT CONDITION
• Is drive belt worn?
• Does it have foreign material imbedded in it, or have oil on it?
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Yes
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Remove obstruction, remove oil, or replace drive belt, then go to Step 13.
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No
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Go to the next step.
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11
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INSPECT MAGNETIC CLUTCH
• Inspect magnetic clutch.
• Is it okay?
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Yes
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Replace A/C compressor (excluding pressure plate, A/C compressor pulley, and stator), then go to Step 13.
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No
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Replace magnetic clutch, then go to Step 13.
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12
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CHECK TO SEE WHETHER MALFUNCTION IS IN A/C COMPRESSOR OR REFRIGERANT LINES
• Is noise coming from A/C compressor?
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Yes
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Visually inspect A/C compressor, replace appropriate parts if necessary, then go to next step.
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No
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If noise is coming from refrigerant lines, repair any detached or missing clips, tighten loose bolts, then go to the next step.
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13
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CONFIRM THAT MALFUNCTION SYMPTOMS DO NOT RECUR AFTER REPAIR
• Has A/C compressor noise stopped?
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Yes
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Troubleshooting completed. Explain repairs to customer.
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No
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Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.
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