For 1990-2009 cars

# WHISTLING NOISE FROM HVAC DOOR (NEW SERVICE PROCEDURES)

#### SUBJECT: WHISTLING NOISE FROM HVAC TEMPERATURE DOORS - NEW SERVICE PROCEDURE

#### MODELS/YEARS: 1991 NINETY-EIGHT AND TOURING SEDAN

CONDITION: Some early 1991 Ninety-Eight and Touring Sedan models built prior to vehicle number M430955 may exhibit a condition where a whistle is heard coming from the HVAC when the temperature door comes off the full hot position.

CAUSE: The valves mounted on the temperature doors may not be properly sealed. These valves have the appearance of an air scoop.

CORRECTION: Apply a bead of Dow Corning #111 Silicone Grease or equivalent along the temperature door to valve seam as marked in the illustration on the back of this bulletin.

#### CAUTION:

This vehicle is equipped with the Supplemental inflatable Restraint (SIR) System. Refer to cautions in section 9J under on-vehicle service before performing service on or around SIR components or wiring. Failure to follow cautions could result in possible air bag deployment, personal injury or unnecessary SIR system repairs.

#### CAUTION:

Before removing or installing any electrical components, disconnect the negative battery cable to help prevent personal injury and/or damage to the vehicle or its components.

#### Procedure:

----------- 1. Follow sections 8C/1B of the service manual to remove the air distribution duct assembly from the dash. See the illustration.

2. Apply a bead of Dow Corning #111 Silicone Grease or equivalent to the seams where the valves are attached to the temperature door(s) as illustrated.

3. Reassemble the HVAC and dash assembly as per the service manual.

#### WARRANTY INFORMATION:

Labor Operation Number: T5222 Labor Time: 2.2 hours (Add 0.7 hour for console) Trouble Code: 92

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.