CHIRP AT IDLE/ENGINE AREA AIR CHECK VALVE INFORMATION

A "chirping" noise may be experienced from the engine compartment area at idle. This condition may be from the A.I.R. check valve in the air supply line to the catalytic converter.

To determine if this is the case, pinch off the rubber hose between the check valve and the A.I.R. pump while the vehicle is in a fully warmed condition. If the noise stops replace with check valve, Part Number 22048209.

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.