A condition has been experienced on some early 1985 Electras with C68 where a deep roar may be heard several minutes after start up in cold weather. If a car with this condition is experienced, it can be improved by applying a bead of Dow Corning III Compound (or equivalent heavy consistency silicone lubricant) around the temperature door opening. See illustration 1 for area of application. Access to the temperature door opening can be gained by removing the heater outlet. Ttie bead of silicone must be applied to the HVAC Module (Not to the temperature door itself) but must contact the vinyl seal around the entire perimeter of the door when the door is closed.
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.