For 1990-2009 cars

# INTERMITTENT A/C SYSTEM THUMP NOISE ON INITIAL START UP

#### SUBJECT: INTERMITTENT A/C SYSTEM THUMP NOISE ON INITIAL START UP FROM FRONT PASSENGER SIDE FLOOR PANEL (REPLACE ACCUMULATOR)

#### MODELS: 1995-97 BUICK LESABRE, PARK AVENUE 1995-97 OLDSMOBILE EIGHTY EIGHT 1996-97 OLDSMOBILE LSS 1997 OLDSMOBILE REGENCY 1995-97 PONTIAC BONNEVILLE WITH 3.8L ENGINE (VINS K, 1 - RPOS L36, L67)

#### CONDITION:

SOME OWNERS MAY COMMENT ON AN A/C SYSTEM THUMP NOISE. THIS THUMP NOISE IS INTERMITTENT AND CAN OCCUR ONCE DURING AN IGNITION CYCLE. THE SOURCE OF THE "THUMP" APPEARS TO BE THE FRONT PASSENGER SIDE FLOOR PANEL. THIS NOISE CAN ONLY OCCUR WITH THE A/C SYSTEM ON.

#### CAUSE:

THE ACCUMULATOR CAUSES THE THUMP NOISE DUE TO RAPID EVAPORATION OF LIQUID REFRIGERANT THAT HAS COLLECTED IN THE DESICCANT BAG PRIOR TO A/C START-UP.

#### CORRECTION:

THIS CONDITION MAY BE CORRECTED BY REPLACING THE ACCUMULATOR. THE SPECIFIED SERVICE ACCUMULATOR IS SPECIFICALLY DESIGNED TO CORRECT THIS CONDITION AND SHOULD NOT BE SUBSTITUTED FOR OTHER ACCUMULATOR ISSUES. REFER TO SECTION 1B OF THE APPROPRIATE SERVICE MANUAL FOR REPLACEMENT PROCEDURE.

#### PARTS INFORMATION:

DESCRIPTION P/N =========== ===

ACCUMULATOR - A/C 2724961

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

#### WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER: D3280 USE PUBLISHED LABOR OPERATION TIME.

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 1997 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.