1500 RPM BOOM CATALYTIC CONVERTER DAMPENER

Models Affected: 1982 - 84 Century and Skylark Vehicles Equipped with 2.5L (VIN Code R) Engine (Including Wagons) Condition --------- Some 1982-1984 Century and Skylark vehicles equipped with the 2.5L engine may exhibit a loud booming noise at 1500 rpm.

Cause

This condition may be caused by the catalytic converter hanger being preloaded.

Correction

To correct this condition the following procedures should be followed:

1. Remove the load from the catalytic converter exhaust hanger.

a. Loosen the converter and manifold flange joint bolts.

b. Break the converter joint loose.

c. Retighten the bolts to 20-40 N-m (15-30 ft. lbs) while holding the converter up against the heat shield.

d. Make sure the distance between the upper and lower converter hanger rivets is less than 62mm.

2. Install a newly released additional cradle dampener assembly (See Illustration).

PART NUMBER DESCRIPTION ------------ ----------- 22527158 Dampener Assembly 10021800 Bolt

Do not remove the existing dampener.

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.