NO.8 NOISE WHILE OPERATING A/C SYSTEM [MANUAL AIR CONDITIONER]
id0702c2812700
8
|
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 vane noise
• A/C compressor slippage noise
• Hose or refrigerant line interference noise
|
Diagnostic procedure
STEP |
INSPECTION |
ACTION |
|
---|---|---|---|
1
|
CHECK A/C COMPRESSOR VANE NOISE
• Is there a jingling, popping, beeping, or buzzing sound (A/C compressor vane noise)?
|
Yes
|
Go to Step 5.
|
No
|
Go to the next step.
|
||
2
|
INSPECT A/C COMPRESSOR SLIPPAGE NOISE
• Is there a squeaking or whirling sound (A/C compressor slippage noise)?
|
Yes
|
Go to Step 14.
|
No
|
Go to the next step.
|
||
3
|
INSPECT A/C COMPRESSOR INTERFERENCE NOISE
• Is there a rattling or vibrating sound (interference noise)?
|
Yes
|
Go to Step 18.
|
No
|
Go to the next step.
|
||
4
|
INSPECT MAGNETIC CLUTCH OPERATION NOISE
• Is there a clicking sound (magnetic clutch operation noise)?
|
Yes
|
Adjust clearance between pressure plate of magnetic clutch and A/C compressor pulley, then go to Step 19.
|
No
|
Condition is normal. (Recheck malfunction symptoms.)
|
||
5
|
INSPECT A/C COMPRESSOR NOISE TIME
• Is noise heard continuously for more than 3 s after A/C compressor comes on?
|
Yes
|
Go to the next step.
|
No
|
Condition is normal. (Noise occurs for 2—3 s immediately after A/C compressor turns on.)
|
||
6
|
INSPECT IDLE SPEED
• Inspect idle speed.
(See ENGINE TUNE-UP [L8, LF].)
• Is it okay?
|
Yes
|
Go to the next step.
|
No
|
Follow the repair instruction described in section F, then go to Step 19.
|
||
7
|
INSPECT REFRIGERANT AMOUNT
• Inspect refrigerant amount.
• Is it okay?
|
Yes
|
Go to Step 10.
|
No
|
Go to the next step.
|
||
8
|
INSPECT REFRIGERANT LINES
• Inspect refrigerant lines.
• Are above items okay?
|
Yes
|
Go to the next step.
|
No
|
If piping or A/C component(s) is damaged or cracked, replace then go to Step 19.
If there is gas leakage, repair or replace connection and replace condenser*1, then go to Step 19.
|
||
9
|
INSPECT EVAPORATOR PIPING CONNECTIONS IN A/C UNIT FOR GAS LEAKAGE
• Are piping connections for evaporator in A/C unit free of gas leakage?
|
Yes
|
Adjust refrigerant amount to specified level, then go to Step 19.
|
No
|
If piping is damaged or cracked, replace then go to Step 19.
If there is gas leakage, repair or replace connection and replace condenser*1, then go to Step 19.
|
||
10
|
CHECK TO SEE WHETHER MALFUNCTION IS IN COMPRESSOR OIL OR ELSEWHERE
• Add 20 ml {20 cc, 0.8 fl oz} of compressor oil.
• Is noise heard when racing engine?
|
Yes
|
Go to the next step.
|
No
|
Troubleshooting completed.
Explain repair to customer.
|
||
11
|
CHECK TO SEE WHETHER MALFUNCTION IS IN A/C COMPRESSOR OR ELSEWHERE
• Drain compressor oil.
• Is it contaminated with metal particles?
|
Yes
|
Go to the next step.
|
No
|
Replace A/C compressor, then go to Step 19.
|
||
12
|
CHECK TO SEE WHETHER MALFUNCTION IS SOMEWHERE IN A/C SYSTEM OR ELSEWHERE
• Is compressor oil whitish and mixed with water?
|
Yes
|
Replace A/C compressor, evaporator, expansion valve, condenser and refrigerant line, then go to Step 19. (See A/C COMPRESSOR REMOVAL/INSTALLATION.)
|
No
|
Go to the next step.
|
||
13
|
INSPECT A/C COMPRESSOR OIL
• Is compressor oil darker than normal and contaminated with aluminum chips?
|
Yes
|
Replace A/C compressor and condenser, then go to Step 19. (Since A/C compressor may be worn and receiver/drier may be clogged, replacement of receiver/drier is necessary.)
|
No
|
Condition is normal. Recheck malfunction symptoms.
|
||
14
|
CHECK TO SEE WHETHER MALFUNCTION IS IN A/C COMPRESSOR OR ELSEWHERE
• Is noise heard immediately after A/C compressor is stopped?
|
Yes
|
Replace A/C compressor, then go to Step 19. (A/C compressor discharge valve left open)
|
No
|
Go to the next step.
|
||
15
|
INSPECT DRIVE BELT
• Inspect drive belt.
• Is it okay?
|
Yes
|
Go to the next step.
|
No
|
Adjust or replace drive belt, then go to Step 19.
|
||
16
|
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 19.
|
No
|
Go to the next step.
|
||
17
|
INSPECT MAGNETIC CLUTCH
• Inspect magnetic clutch.
• Is it okay?
|
Yes
|
Replace A/C compressor (excluding pressure plate, A/C compressor pulley, and stator), then go to Step 19.
|
No
|
Replace magnetic clutch, then go to Step 19.
|
||
18
|
CHECK TO SEE WHETHER MALFUNCTION IS IN A/C COMPRESSOR OR REFRIGERANT LINES
• Is noise emitted from A/C compressor?
|
Yes
|
Visually inspect A/C compressor, replace appropriate parts if necessary, then go to the next step.
|
No
|
If noise is due to refrigerant lines, repair detached or missing clips, tighten loose bolts, then go to the next step.
|
||
19
|
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.
|