Idle Vibration and/or Boom Noise While A/C is On

Some customers may comment about a vibration or boom noise inside the vehicle while at idle and the A/C is ON. The vibration or boom may also be more noticeable while vehicle is in gear.

Exhaust system exhibits resonance at idle while A/C is On.

Install tuned mass damper onto intermediate exhaust pipe.

Caution: Make sure vehicle is properly supported and squarely positioned on hoist. To help avoid personal injury, provide additional support to the opposite end of vehicle that components are removed from.

1. Verify the condition by following these steps:
2. Start the engine and make sure vehicle is at operating temperature at idle and A/C is On.

Important: The vibration or boom is most noticeable with vehicle in gear.

•	If vibration or boom is recognized, proceed to step 3.

•	If vibration or boom noise is not recognized, refer to "Exhaust System Diagnostic Chart" in the Exhaust Section of the 2001 or 2002 L Series (L81) Engine Service Manual.

3. Raise vehicle on a hoist.




Important: For proper operation, the tuned mass damper must be installed in the horizontal position (parallel to the floor pan).

4. Install tuned mass damper P/N 22677146 to left side of intermediate pipe forward of the "Y" and just behind the flange for the front exhaust manifold pipe. Use clamp P/N 2680645 to attach the damper. Make certain the damper is horizontal and does not contact any part of the exhaust system, heat shields, or body as the exhaust system moves.

Tighten
Tighten the Exhaust Pipe Clamp to 35 N·m (26 lb ft).

5. Lower vehicle.
6. Verify repair.

To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Dealer System as follows: