Heating/A/C - Whistling Noise From The Blower Motor: Overview
85 Whistling noise from HVAC blower85 12 07
2021669/4
July 23, 2012.
Supersedes Technical Service Bulletin Group 85 number 11 - 04 dated March 21, 2011 for reasons listed below.
Affected Vehicles
Condition
Whistling noises proceed from the air outlets when the HVAC system is operating.
Technical Background
The whistling noise can be caused by one or more of the following known root causes.
Condition 1
The noise is heard only when the interior of the car is cold and the blower speed is set within the range of medium to high.
Root Cause:
The seals on the temperature flaps were changed to a single lip design and leak air when in full heating mode with blower speed settings of 6-12.
Condition 2
The noise is heard only during the first 10 minutes of defrost mode with blower speeds of 6 or 7.
Root Cause:
The locking tabs for the second-row floor duct to the front HVAC unit leak air.
Condition 3
The noise is heard only when in panel vent mode and at any temperature setting.
Root Cause:
An access hole in the HVAC system was not completely sealed from the factory.
Condition 4
The noise is heard at any temperature setting, regardless of air distribution mode and only when the blower is set to within a range of medium to high.
Root Cause:
The screws holding the two halves of the air distribution unit are not tightened properly and allow air to leak out the seam.
Production Solution
The temperature flap seals now have a dual lip design that improves the sealing of the doors.
The access hole is plugged. The rear duct for the second-row vents is taped off.
Warranty
All warranty claims submitted for payment must be in accordance with the Audi Warranty Policies and Procedures Manual. Claims are subject to review or audit by Audi Warranty.
Required Parts and Tools
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service manuals for the latest information.