Subject: | Engine Buzz or Rattle Noise at Wide Open Throttle |
Models: | 2007 Cadillac Escalade |
2007 Chevrolet Avalanche, Tahoe |
2007 GMC Yukon |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
The customer concern may be a engine buzz or rattle noise heard only when driving the vehicle at wide open throttle (WOT).
Verify the customer concern, and use the Chassis Ears to pinpoint any rattle noises.
The buzz noise heard from the engine compartment at WOT may be described and diagnosed as a engine noise. The noise will occur in the 4000 to 5000 RPM range. If chassis ears and normal SI diagnostics are inconclusive, inspect the hood hinge retaining bolt torque. The outboard sections of the Air Inlet Grille need to be removed to access the hood hinge retaining bolt. (See SI procedure for Air Inlet Grille Panel Replacement)
If the hood hinge bolt is found loose, torque the hood hinge bolt using SI torque specifications.
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.