I had a knocking behind my dash upon start up, took the glove box down, looked around behind there, put it back up, knocking gone! I DID NOTHING BUT LOOK! Wth?

 

What kind of knocking? Like a few loud knocks as if someone is tapping the underside of your dash with a hammer?

 

Sounds like Recirc. Actuator...

 

I counted them when it was still doing it...... 20 knocks..... It isn't doing it anymore tho.....

 

Damn......... It's knocking again!

 

I have the same issue...

 

It must be Walter White

 

EXACTLY!!!!!! WTF is that?? Is it the actuator door like he said??

 

Never heard that... huh very wierd

 

Only this, and nothing more.

 

Yes, that's the exact noise I was getting at and that's the cause. Same thing is broken on my mom's 2006 Cobalt.

Try this - turn car on, and immediately upon hearing the knocking sound press the recirc button and it should stop right away. That should confirm the diagnosis.


...anyone know how to replace this?

 

I believe this is the replacement part. No idea on how to replace it though!

 

Anyway, I've never heard that with either of my Cobalts. Sounds like impending doom to me.

 

confirmed!!!!!

 

Pretty common noise actually. More so in impalas but sometimes in cobalts. The gears inside the actuator get stripped or out of adjustment. Then the counts get off and it has no idea what location its in. so it keeps trying to close/open when it already is, causing that noise.

 

And there is no recall on this?

 

I have had this problem for over a year now. Sub'd.

 

Nope no recall. Recalls only pertain to safety defects. They have bulletins out for this but those are just for making common issues more well known for quicker diagnostics.