Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
The problem you are having is very common but there is no recall. What you are hearing is a door actuator. This is a small electrical motor that moves the temp doors or the recirculation door. When the actuator goes bad, you will hear a thump noise from under the dash, about one thump a second. To repair this, you need to replace the actuator. The actuators run about $55 each and can be replaced at home. What you need to do is find out which actuator is bad, they are all the same part number but are located in different areas of the dash. Since you hear it from the passengers side, it may be the passengers temp door or the recir door actuator. If you lower the glove box door you can see the actuators. The glove box door opens all the way by pressing the stop tabs on the inside of the glove box, you should be able to see the stops by opening the glove box and see what is stopping it from opening further. You will see the stops, push them in so you can open the glove box. The passengers temp door actuator is located towards the center of the dash and the recir door located at the outer side of the dash. Put you hand on the actuators when they are making the noise and you can feel which actuator is bad. Replace that actuator by removing the screws (2) that hold it on. Then you are finished with the repair.
Here is the recir door actuator called a air inlet actuator.
Air Inlet Valve Actuator Replacement
Attachments are only available to registered users.
The right side listed as number 2.
Temperature Valve Actuator Replacement - Right Side