When I start my Mazda 3, there’s a loud clicking noise from the front vent. It only lasts 20-30 seconds and doesn’t come back until the next time I start up. If I press the recycle air button, it stops immediately. Any idea what might be wrong?
Sounds like (pun intended) one of the actuator motors in the HVAC system is going bad.
There are motors with sensors inside them that control the airflow and direction in your Mazda’s HVAC system. These cycle upon startup so the computers “know” what position they are in. The computer drives the actuator until it stops moving and then drives it back the other way so the computer knows the range. If the gears inside the actuator get a bit worn, they “click”. If worn a bit more, they quit moving all together.
Or possibly it is jammed and won’t move at all. The computer moves it for 20 seconds and then gives up.
If the air flow stops going where you set the controls, that is the problem. Otherwise, live with the clicking until that happens.