EXHAUST BOOM/A,F,X/2.5L 4-CYL. REPOSITION REAR EXH. HANGERS

Listed below are various correction procedures used to improve idle shake or instrument panel/steering wheel vibration conditions. Five of the correction procedures are already technical or information bulletins while the remaining seven procedures are new.

Idle Shake Noise, Instrument Panel/Steering Wheel Vibration - 1982-1983 Phoenix And 6000 Models

1. (82-T-17A) - 1700 to 2000 RPM cradle moan/vibration.

2. (82-T-1 8) - Engine torque strut preload adjustment.

3. (82-1-195) - PROM update to increase idle speed (3-board ECM).

4. Power steering hoses contacting the A/C accumulator have a significant effect on the instrument panel vibrations at idle. These hoses should be pulled away from the accumulator so that no contact occurs.

5. Engine cradle misalignment can influence idle shake. The cradle should be properly aligned using the three alignment holes near the cradle support bushings.

6. Excess rubber in either or both of the transmission mount interlock windows will influence idle vibration (see Figure 1). This rubber can be cut away with the mounts on the vehicle.

7. Check for an unrelaxed rubber exhaust hanger rearward of the catalytic converter (see Figure 2 on the reverse side). At predominantly 1800 rpm (road load) or idle, the unrelaxed hanger will transmit vibration through the floor pan and body structure. If this condition exists, loosen the exhaust joint ball flange, reposition the catalytic converter upwards to unload the hanger, and retighten the exhaust system flange bolts to 20-24 Nm (15-17 ft. lbs.). Visual checks for the exhaust system contacting the body should also be made.

8. Loose, improperly installed, or missing instrument panel fasteners will contribute to idle vibration.

Vibration, Buzz, Growl Or Boom - 1982-1983 Firebird Models

9. (82-T-44) - 3600 to 4800 RPM engine growl/vibration.

10. (82-1-209) - 4000 RPM boom/vibration.

11. Idle Through 2500 RPM - Vibration/Buzz - This condition could be caused by either or both front engine mounts grounding out. To correct this condition, install a 4.6mm (3/16") thick flat washer in the locations shown in Figure 3 (below) of the suspect mount(s).

12. Cold Weather Engine Vibration/Idle Shake At 40 DEG F And Below - A cold weather related engine vibration/idle shake may be caused by the front engine mounts. This condition may diminish after the vehicle has warmed at moderately cold temperatures (25-40 DEG F) but may never leave at very cold temperatures.

This condition may be corrected by replacing both front engine mounts with part number 10029901 (right side) and 10029902 (left side).

1983 vehicles built after the following VIN breakpoints are not affected:

Norwood DN214918 Van Nuys DL208854

WARRANTY INFORMATION CORRECTION LABOR TIME TROUBLE PROCEDURE OPERATION ALLOWANCE CODE T3106 36 2 T3107 .2 36 3 T3108 .5 36 4 T3109 .2 36 5 T3110 .4 36 6 T3111 .2 36 7 T3112 .3 36 8 T3113 .2 36 9 T3075 .9 36 10 T3114 .3 36 11 T3115 .8 36 12 T3116 .9 36

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.