Air Conditioning System: NVH — Air Conditioning System — Automatic HVAC System

Air Conditioning System: NVH Suzuki Aerio I

Abnormal Noise from Compressor

Condition	Possible Cause	Action
Compressor: During compressor operation, a rumbling noise is heard proportional to engine revolutions .	Inadequate clearance in piston area (piston or swash-plate)	Repair or replace compressor as necessary .
Compressor: A loud noise is heard at a certain rpm, disproportionately to engine revolution .	Loose or faulty compressor drive belt	Replace drive belt.
	Loose compressor mounting bolts	Retighten mounting bolts.
Compressor: A loud rattle is heard at low engine rpm .	Loose compressor clutch plate bolt	Retighten clutch plate bolt. Replace compressor if it was operated in this condition for a long time .

A/C SYSTEM PROBLEM SYMPTOMS DIAGNOSTIC CHART (ABNORMAL NOISE FROM COMPRESSOR)

Condition	Possible Cause	Action
Magnet Clutch: A rumbling noise is heard when compressor is not operating .	Worn or damaged bearings	Replace magnet clutch assembly .
Magnet Clutch: A chattering noise is heard when compressor is engaged .	Faulty clutch clearance (excessive)	Adjust clutch clearance .
	Worn clutch friction surface	Replace magnet clutch assembly .
	Compressor oil leaked from shaft seal, contaminating the friction surface	Replace compressor body assembly .

A/C SYSTEM PROBLEM SYMPTOMS DIAGNOSTIC CHART (ABNORMAL NOISE FROM MAGNETIC CLUTCH)

Condition	Possible Cause	Action
Tubing: A droning noise is heard inside vehicle, but not particularly noticeable in engine compartment .	Faulty tubing clamps	Reposition clamps or increase the number of clamps .
	Resonance caused by pulsation from variations in refrigerant pressure	Attach a silencer to tubing, or modify its position and length .

A/C SYSTEM PROBLEM SYMPTOMS DIAGNOSTIC CHART (ABNORMAL NOISE FROM TUBING)

Condition	Possible Cause	Action
Condenser: Considerable vibration in condenser .	Resonance from condenser bracket and body	Firmly insert a silencer between condenser bracket and body .

A/C SYSTEM PROBLEM SYMPTOMS DIAGNOSTIC CHART (ABNORMAL NOISE FROM CONDENSER)

Condition	Possible Cause	Action
Crankshaft Pulley: A large rattling noise is heard at idle or sudden acceleration .	Loosen crankshaft pulley bolt	Retighten bolt .

A/C SYSTEM PROBLEM SYMPTOMS DIAGNOSTIC CHART (ABNORMAL NOISE FROM CRANKSHAFT PULLEY)

Condition	Possible Cause	Action
Tensioner Pulley: Clattering noise is heard from pulley .	Worn or damaged bearing	Replace tensioner pulley .
Tensioner Pulley: Pulley cranks upon contact .	Cracked or loose bracket	Replace or retighten bracket .

A/C SYSTEM PROBLEM SYMPTOMS DIAGNOSTIC CHART (ABNORMAL NOISE FROM TENSIONER PULLEY)

Condition	Possible Cause	Action
A/C Evaporator: Whistling sound is heard from A/C evaporator .	Depending on the combination of the interior / exterior temperatures, engine rpm and refrigerant pressure, the refrigerant flowing out of the expansion valve may, under certain conditions, make a whistling sound	At times, slightly decreasing refrigerant volume may stop this noise. Inspect expansion valve and replace if faulty .

A/C SYSTEM PROBLEM SYMPTOMS DIAGNOSTIC CHART (ABNORMAL NOISE FROM A/C EVAPORATOR)