For 1990-2009 cars

# WHISTLE NOISE FROM HVAC WHEN COMING OFF FULL HOT POSITION

#### SUBJECT: WHISTLE NOISE FROM HVAC WHEN COMING OFF FULL HOT POSITION (TRIM TEMPERATURE VALVE)

#### MODELS: 1992-96 BUICK LESABRE, PARK AVENUE 1996 CADILLAC ELDORADO, SEVILLE 1992-96 OLDSMOBILE EIGHTY EIGHT, NINETY EIGHT BUILT PRIOR TO DECEMBER 1, 1995 WITH RPO CJ2

#### CONDITION:

SOME OWNERS MAY COMMENT ON A WHISTLE NOISE FROM THE HVAC WHEN COMING OFF THE FULL HOT POSITION.

#### CAUSE:

THE ABOVE CONDITION OCCURS AS THE PASSENGER TEMPERATURE MIX VALVE STARTS TO MOVE AWAY FROM THE FULL HOT POSITION. THE TEMPERATURE VALVE DOES NOT COME OFF ITS SEAT EVENLY, CAUSING A SMALL "LEAK". THE WHISTLE IS ORIGINATING THROUGH THIS LEAK.

#### CORRECTION:

THE PASSENGER TEMPERATURE VALVE NEEDS TO BE TRIMMED TO PREVENT THE WHISTLE. APPROXIMATELY 12MM (1/2 INCH) OF MATERIAL NEEDS TO BE REMOVED FROM THE PASSENGER TEMPERATURE VALVE. THE ATTACHED FIGURE IS THE ACTUAL SIZE OF THE VALVE AND ILLUSTRATES THE AMOUNT OF MATERIAL THAT NEEDS TO BE REMOVED. USE THE REPAIR PROCEDURE BELOW TO ACCESS THE PASSENGER TEMPERATURE VALVE.

BEFORE BEGINNING THE REPAIRS, SET THE HVAC CONTROLS FOR THE DRIVER AND PASSENGER TO 90 DEGREES FAHRENHEIT (32 DEGREES CELSIUS) SET TEMPERATURE.

REMOVE OR DISCONNECT -

1. NEGATIVE BATTERY CABLE.

2. RELAY CENTER COVER.

3. PINCH HEATER HOSES.

4. HEATER HOSES FROM HEATER CORE, USING J 37097-A.

5. I/P COMPARTMENT ASSEMBLY AND RIGHT-SIDE SOUND INSULATOR.

6. PROGRAMMER (C/H CARS ONLY).

7. AIR VALVE VACUUM HARNESS FROM PROGRAMMER (E/K CARS ONLY).

8. RETAINING SCREWS AND HEATER CORE COVER. CARPET MAY HAVE TO BE REPOSITIONED TO REMOVE COVER.

9. RETAINING SCREWS AND HEATER CORE FROM VEHICLE.

10. POSITION THE PASSENGER TEMPERATURE VALVE (UPPER DOOR) AND TRIM CORNER OF PASSENGER TEMPERATURE VALVE (UPPER DOOR). REFER TO ATTACHED FIGURE, ILLUSTRATION IS TO SCALE AND IS TO BE USED AS A REFERENCE.

INSTALL OR CONNECT -

1. HEATER CORE INTO VEHICLE AND ATTACHING SCREWS. - SCREWS TO 1.4 N.M (12 LB IN).

2. HEATER CORE COVER AND ATTACHING SCREWS. CARPET MAY HAVE TO BE REPOSITIONED TO INSTALL COVER. - SCREWS TO 1.4 N.M (12 LB IN).

3. PROGRAMMER (C/H CARS ONLY). - SCREWS TO 1.4 N.M (12 LB IN).

4. AIR VALVE VACUUM HARNESS TO PROGRAMMER (E/K CARS ONLY).

5. RESET TEMPERATURE LINK RODS. CONNECT LINK ROD WITH VALVE IN THE MAX HEAT POSITION.

6. I/P COMPARTMENT ASSEMBLY AND RIGHT-SIDE SOUND INSULATOR.

7. HEATER HOSES TO HEATER CORE USING TOOL J 37097-A.

8. CHECK LEVEL OF COOLING SYSTEM.

9. NEGATIVE BATTERY CABLE.

#### WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER: D2802 LABOR TIME: 0.8 HR (BUICK, OLDSMOBILE) 1.2 HR (CADILLAC)

FIGURES: 01 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.