For 1990-2009 cars

# A/C SYSTEM FLUTTER AND/OR MOAN NOISE WITH HVAC IN A/C MODE

#### SUBJECT: A/C SYSTEM FLUTTER AND/OR MOAN NOISE WITH HVAC IN A/C MODE (REPLACE A/C COMPRESSOR HOSE ASSEMBLY)

#### MODELS: 1996 BUICK PARK AVENUE 1996-97 BUICK LESABRE 1996 OLDSMOBILE NINETY EIGHT 1996-97 OLDSMOBILE EIGHTY EIGHT, LSS, REGENCY 1996-97 PONTIAC BONNEVILLE WITH 3.8L ENGINE (VINS K, 1 - RPOS L36, L67)

#### CONDITION:

SOME OWNERS MAY COMMENT ON A "FLUTTERING" AND/OR "MOAN" NOISE DURING NORMAL DRIVING CONDITIONS WITH THE HVAC SYSTEM IN THE "A/C" MODE. THE NOISES BECOME EVIDENT UNDER LIGHT ACCELERATION OR DECELERATION WITH THE A/C COMPRESSOR CLUTCH ENGAGED. THE NOISES ARE EVIDENT IN THE GLOVE BOX AREA OF THE INTERIOR OF THE VEHICLE. THE NOISES ARE MOST NOTICEABLE WITH THE HVAC BLOWER SET ON LOW SPEED WITH THE ENGINE OPERATING BETWEEN IDLE AND 2500 RPM.

#### CAUSE:

THE "FLUTTER" AND/OR "MOAN" NOISES ARE CREATED BY PRESSURE PULSES GENERATED BY THE A/C COMPRESSOR. THE A/C COMPRESSOR HOSE ASSEMBLY TRANSMITS THESE PRESSURE PULSES INTO THE BODY OF THE VEHICLE THROUGH THE HVAC MODULE.

#### CORRECTION:

THIS CONDITION MAY BE CORRECTED BY REPLACING THE A/C COMPRESSOR HOSE ASSEMBLY WITH A NEW COMPRESSOR HOSE ASSEMBLY, P/N 25665518. THE NEW COMPRESSOR HOSE ASSEMBLY CONTAINS AN ADDITIONAL MUFFLER LOCATED ON THE SUCTION LINE (LOW PRESSURE SIDE OF THE A/C SYSTEM). THE ADDITIONAL MUFFLER DAMPENS THE COMPRESSOR PRESSURE PULSES. REFER TO SECTION 1B OF THE APPROPRIATE SERVICE MANUAL FOR REPLACEMENT PROCEDURE.

#### PARTS INFORMATION:

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

#### WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER DESCRIPTION LABOR TIME =============== =========== ==========

D3088 HOSES AND/OR LINES - USE PUBLISHED REFRIGERANT - REPLACE LABOR OPERATION (COMPRESSOR SUCTION + TIME DISCHARGE HOSE ASSEMBLY)

ADD: RECOVER/RECHARGE A/C 0.7 HR SYSTEM

FIGURES: 00 ATTACHMENTS: 00

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION. SEE A GENERAL MOTORS DEALER SERVICING YOUR BRAND OF GENERAL MOTORS VEHICLE FOR INFORMATION ON WHETHER YOUR VEHICLE MAY BENEFIT FROM THE INFORMATION.

COPYRIGHT 1996 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.