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Exhaust System - Loud Booming Noise at 1500 RPM

Bulletin 84-6F-2

Date May '84

Ref. No. 84-222-6
SUBJECT: 1500 RPM BOOM

MODELS AFFECTED: 1982-84 CENTURY AND SKYLARK VEHICLES
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 62 mm.

CRADLE DAMPENER ASSEMBLY:




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.