RATTLE OR BUZZ NOISE FROM THE INSTRUMENT PANEL

1987-88 FIRENZA, CALAIS MODELS EQUIPPED WITH C60

Some Firenza and Calais car owners may comment on a metallic rattle or buzzing noise coming from center of the instrument panel.

Under certain road or engine load conditions, with the A/C system on, the metal defroster valve in the A/C module assembly may vibrate against the plastic case causing the noise. The noise may be heard in all modes except defrost.

The following procedure should be followed to address this condition:

CORRECTION:

----------- 1. Remove right side insulator assembly. See Figure 1.

2. Remove duct assembly, floor air outlet. See Figure 2.

3. Secure a 1" long piece of 7/16" windshield washer hose (or equivalent) and cut one side the full 1" length so that the hose can be slipped over the edge of the defroster valve.

4. Apply RTV silicone rubber adhesive sealant to the inside of the 1" piece of rubber hose.

5. Set mode lever on control panel to defrost position. This will expose the edge of the defroster valve.

6. Reach through the duct opening in the module assembly and push the 1" piece of hose with sealant onto the exposed edge of the metal defroster door. See Figure 3.

CAUTION:

Ample cure time for RTV sealant must be allowed to insure rubber hose adheres to the valve.

7. Reassemble floor air outlet duct assembly and right side insulator assembly.

WARRANTY INFORMATION .

Labor Operation Number: T4636 Labor Time: .4 hrs. 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.