High Pitch Whistle Noise From HVAC - keywords air case dash fresh front ip off open recirculation
| Subject: | High Pitch Whistle Noise From HVAC |
| Models: | 2007 Chevrolet Silverado Extended or Crew Cab Models |
| 2007 GMC Sierra Extended or Crew Cab Models |
| With RPO C67 |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some owners may comment of a high pitch whistle noise while driving at highway speeds with the HVAC system off. This noise may occur if the recirculation door is in the Recirculation mode, and will go away if put in Fresh Air mode. This noise is caused by air whistle between the recirculation door and HVAC case.
Recommendation/Instructions:
To correct this concern install 1/2 inch (12.5 mm) wide by 1/8 inch (3 mm) thick open cell foam tape on the recirculation door. The foam tape should be applied along both sides and along the hinge side of the door as shown below. Before installing the foam tape clean the door with denatured alcohol, acetone, or equivalent in the area that the tape will be applied.
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.
