09 hhr ss automatic.
When I start the car I hear what sounds like a relay thumping.
I happens a few seconds after the car has started.
It thumps about a dozen times an then stops.
I sounds like it is coming from behind the glove box.
Everything seems to be working.

Any ideas?

Thanks

 

My guess would be a hvac actuator in its beginning to fail.

That have plastic gears in them and jump gear teeth when there worn.

You can try and change the control settings temp. & mode to see if the noise is there when the actuators move.