NO.6 NOISE WHILE OPERATING A/C SYSTEM

6	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

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 13.
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 17.
No	Go to next step.
3	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 18. (See MAGNETIC CLUTCH ADJUSTMENT.)
No	Go to next step.
4	INSPECT A/C COMPRESSOR NOISE TIME • Is noise heard continuously for 3 s or more after A/C compressor comes on?	Yes	Go to next step.
No	Condition is normal. (Noise occurs for 2—3 s immediately after A/C compressor turns on.)
5	INSPECT IDLE SPEED • Inspect idle speed. • Is it normal?	Yes	Go to next step.
No	Follow the repair instruction described in section 01, then go to Step 18.
6	INSPECT REFRIGERANT AMOUNT • Inspect refrigerant amount. • Is it normal?	Yes	Go to Step 9.
No	Go to next step.
7	INSPECT REFRIGERANT LINES • Inspect refrigerant lines. ― Is piping free of damage and cracks? ― Are piping connections free of oil grime? (Visual inspection) ― Are piping connections free of gas leakage? ― Are piping installation points on condenser free of gas leakage? ― Are piping installation points on receiver/drier free of gas leakage? ― Are piping installation points on A/C compressor free of gas leakage? ― Are piping installation points on cooling unit free of gas leakage ― Perform gas leak inspection using gas leak tester. • Are above items normal?	Yes	Go to next step.
No	If piping or A/C component (s) is damaged or cracked, replace then go to Step 18. If there is gas leakage, repair or replace connection and replace condenser*, then go to Step 18.
8	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 18.
No	If piping is damaged or cracked, replace then go to Step 18. If there is gas leakage, repair or replace connection and replace condenser*, then go to Step 18.
9	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 next step.
No	Troubleshooting completed. Explain repair to customer.
10	CHECK TO SEE WHETHER MALFUNCTION IS IN A/C COMPRESSOR OR ELSEWHERE • Drain compressor oil. • Is it contaminated with metal particles?	Yes	Go to next step.
No	Replace A/C compressor, then go to Step 18.
11	CHECK TO SEE WHETHER MALFUNCTION IS SOMEWHERE IN A/C SYSTEM OR ELSEWHERE • Is compressor oil whitish and mixed with water?	Yes	Replace entire A/C system (excluding heater), then go to Step 18.
No	Go to next step.
12	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 18. (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.
13	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 18. (A/C compressor discharge valve left open)
No	Go to next step.
14	INSPECT DRIVE BELT • Inspect drive belt. (See DRIVE BELT INSPECTION[AJ (3.0L Duratec)].) (See DRIVE BELT INSPECTION[L3].) • Is it normal?	Yes	Go to next step.
No	Adjust or replace drive belt, then go to Step 18.
15	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 18.
No	Go to next step.
16	INSPECT MAGNETIC CLUTCH • Inspect magnetic clutch. • Is it normal?	Yes	Replace A/C compressor (excluding pressure plate, A/C compressor pulley, and stator), then go to Step 18.
No	Replace magnetic clutch, then go to Step 18.
17	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 next step.
No	If noise is due to refrigerant lines, repair detached or missing clips, tighten loose bolts, then go to next step.
18	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.

STEP

INSPECTION

ACTION

INSPECT A/C COMPRESSOR SLIPPAGE NOISE

• Is there a squeaking or whirling sound (A/C compressor slippage noise)?

Yes

Go to Step 13.

Go to next step.

INSPECT A/C COMPRESSOR INTERFERENCE NOISE

• Is there a rattling or vibrating sound (interference noise)?

Yes

Go to Step 17.

Go to next step.

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 18.

(See MAGNETIC CLUTCH ADJUSTMENT.)

Go to next step.

INSPECT A/C COMPRESSOR NOISE TIME

• Is noise heard continuously for 3 s or more after A/C compressor comes on?

Yes

Go to next step.

Condition is normal. (Noise occurs for 2—3 s immediately after A/C compressor turns on.)

INSPECT IDLE SPEED

• Inspect idle speed.

• Is it normal?

Yes

Go to next step.

Follow the repair instruction described in section 01, then go to Step 18.

INSPECT REFRIGERANT AMOUNT

• Inspect refrigerant amount.

• Is it normal?

Yes

Go to Step 9.

Go to next step.

INSPECT REFRIGERANT LINES

• Inspect refrigerant lines.

― Is piping free of damage and cracks?

― Are piping connections free of oil grime? (Visual inspection)

― Are piping connections free of gas leakage?

― Are piping installation points on condenser free of gas leakage?

― Are piping installation points on receiver/drier free of gas leakage?

― Are piping installation points on A/C compressor free of gas leakage?

― Are piping installation points on cooling unit free of gas leakage

― Perform gas leak inspection using gas leak tester.

• Are above items normal?

Yes

Go to next step.

If piping or A/C component (s) is damaged or cracked, replace then go to Step 18.

If there is gas leakage, repair or replace connection and replace condenser*, then go to Step 18.

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 18.

If piping is damaged or cracked, replace then go to Step 18.

If there is gas leakage, repair or replace connection and replace condenser*, then go to Step 18.

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 next step.

Troubleshooting completed.

Explain repair to customer.

CHECK TO SEE WHETHER MALFUNCTION IS IN A/C COMPRESSOR OR ELSEWHERE

• Drain compressor oil.

• Is it contaminated with metal particles?

Yes

Go to next step.

Replace A/C compressor, then go to Step 18.

CHECK TO SEE WHETHER MALFUNCTION IS SOMEWHERE IN A/C SYSTEM OR ELSEWHERE

• Is compressor oil whitish and mixed with water?

Yes

Replace entire A/C system (excluding heater), then go to Step 18.

Go to next step.

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 18. (Since A/C compressor may be worn and receiver/drier may be clogged, replacement of receiver/drier is necessary.)

Condition is normal. Recheck malfunction symptoms.

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 18. (A/C compressor discharge valve left open)

Go to next step.

INSPECT DRIVE BELT

• Inspect drive belt.

(See DRIVE BELT INSPECTION[AJ (3.0L Duratec)].)

(See DRIVE BELT INSPECTION[L3].)

• Is it normal?

Yes

Go to next step.

Adjust or replace drive belt, then go to Step 18.

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 18.

Go to next step.

INSPECT MAGNETIC CLUTCH

• Inspect magnetic clutch.

• Is it normal?

Yes

Replace A/C compressor (excluding pressure plate, A/C compressor pulley, and stator), then go to Step 18.

Replace magnetic clutch, then go to Step 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 next step.

If noise is due to refrigerant lines, repair detached or missing clips, tighten loose bolts, then go to next step.

VERIFY THAT MALFUNCTION SYMPTOM OCCURS AFTER REPAIR

• Has A/C compressor noise stopped?

Yes

Troubleshooting completed.

Explain repairs to customer.

Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.

* :If there is gas leakage, air enters into the A/C system. The desiccant within the receiver/drier absorbs the moisture from the air and becomes saturated. If the A/C system is used in this condition, the inside of the A/C compressor will begin to rust due to this moisture, which may cause lock up or noise to occur. Therefore, replacement of the receiver/drier is necessary.