Exhaust Rumble Rattle Moan Drone Vibration - keywords suspension leak noise manifold pipe muffler
| Subject: | Exhaust Rumble Rattle Moan Drone Vibration |
| Models: | 2006 Chevrolet Silverado |
| 2006 GMC Sierra |
| with 4.3L LU3 |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some customers may comment on an underbody (suspension) rattle/rumble noise on Silao (G in VIN position #11) built 2006 MY full size pickups, with the 4.3 L (RPO LU3) engine built prior to January, 2006. This concern could be cause by an improperly torqued exhaust manifold cross over pipe.
Recommendation/Instructions:
To correct this concern, loosen both the left and right exhaust manifold pipe nuts and re-torque as follows:
- Torque the left exhaust manifold pipe bolts in the sequence indicated below to 37 lb ft (50 Nm).
- Torque the right exhaust manifold pipe bolts in the sequence indicated below to 37 lb ft (50 Nm).
Important: The left exhaust MUST be torqued first.
Note: Callout 3 points to the rear bolt, which is not viewable in the drawing.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
