my girlfriend bought a cobalt about six months ago 2006 2.2L and when she turns on the heater there is a fast paced clicking noise and it does not stop. it has been doing this since she bought it. maybe some kind of motor doing this??? i believe it does it when the air conditioner is on as well.

 

there are probably leaves in the fan.
under the right side of the dash you'll see a motor....take it out and clean it up

 

It sounds like the ticking/clicking comes from the passanger side airbag area in the dashboard.

It isn't leaves in the squirrel cage of the blower unit.
I hope it isnt some issue related to the airbag relays...HELP

 

like he said take it out and clean it, if still doing it after, then replace

 

i had that same problem with mine, got it replaced, but now its making the same noise but now only when its i start it after sitting all night. who knows what the problem, my dealer said to bring it in and they will look at it if it keeps making the noise, i have to leave it there over night so they can start it cold