For 1990-2009 cars

# MOAN OR CHIRPING NOISE FROM A.I.R. SYSTEM

#### MODELS AFFECTED: 1982-84 DE VILLES, FLEETWOODS AND '85 FLEETWOOD BROUGHAMS EQUIPPED WITH HT4100 ENGINES

Some 1982-84 De Villes, Fleetwoods and 1985 Fleetwood Broughams equipped with HT4100 engines may exhibit a moan or chirping noise from the A.I.R. system at idle due to the catalytic convertor air injection check valve. A malfunctioning check valve can be identified by pinching off the rubber hose which feeds air from the air switch valve to the catalytic convertor. If the noise stops when the hose is pinched, replace the catalytic convertor air injection check valve with P/N 22048209. The new part should be black with a white dot painted on it.

For warranty purposes use labor Operation J6086 for .3 hrs.

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.