Suzuki Grand Vitara JB627. Manual - part 278
7B-28 Air Conditioning System:
Abnormal Noise Diagnosis
S6JB0B7204010
There are various types of noise, ranging from those produced in the engine compartment to those from the
passenger compartment, also from rumbling noises to whistling noises.
Abnormal Noise Symptom Diagnosis of A/C System
S6JB0B7204011
Abnormal Noise from Compressor
Cool air does not come
out only intermittently
Wiring connection faulty
Repair as necessary.
Expansion valve faulty
Check expansion valve referring to “Expansion
Valve On-Vehicle Inspection”.
Excessive moisture in A/C system
Replace desiccant, and then perform
evacuation and charge referring to “Operation
Procedure for Charging A/C with Refrigerant”.
Magnet clutch faulty
Check magnet clutch referring to “Magnet
Clutch Operating Check” or “Magnet Clutch
Operating Check”.
Excessive amount of refrigerant
Check the amount of refrigerant.
Cool air comes out only at
high speed
Condenser clogged
Check condenser referring to “A/C Condenser
Assembly On-Vehicle Inspection”.
Insufficient charge of refrigerant
Check the amount of refrigerant and system
for leaks.
Air in A/C system
Replace desiccant, and then perform
evacuation and charge referring to “Operation
Procedure for Charging A/C with Refrigerant”.
Compressor drive belt loosened or
broken
Adjust or replace drive belt.
Compressor faulty
Check compressor.
Cool air does not come
out only at high speed
Excessive amount of refrigerant
Check the amount of refrigerant.
A/C evaporator frosted
Check A/C evaporator and evaporator
temperature sensor referring to “A/C
Evaporator Inspection” and “A/C Evaporator
Temperature Sensor Inspection”.
Insufficient air flow of
cooled air
A/C evaporator clogged or frosted
Check A/C evaporator and evaporator
temperature sensor referring to “A/C
Evaporator Inspection” and “A/C Evaporator
Temperature Sensor Inspection”.
Air leaking from HVAC unit or air duct
Repair as necessary.
Blower motor faulty
Check blower motor referring to “Blower Motor
Inspection in Section 7A”.
Wiring or grounding faulty
Repair as necessary.
Condition
Possible cause
Correction / Reference Item
Condition
Possible cause
Correction / Reference Item
During compressor
operation, a rumbling
noise is heard
proportional to engine
revolutions
Inadequate clearance in scroll area
Replace compressor.
A loud noise is heard at a
certain rpm,
disproportionately to
engine revolution
Loose or faulty compressor drive belt
Adjust drive belt tension or replace drive belt.
Loose compressor mounting bolts
Retighten mounting bolts.
A loud rattle is heard at
low engine rpm
Loose compressor armature plate bolt
Retighten armature plate bolt.
Replace compressor if it was operated in this
condition for a long time.