[lgmII]

I have a knocking noise that sounds like it is coming from within the dashboard on the right hand side. It sounds like something is rotating and tapping against something. It happens only when the engine is running and when the engine is turned off it continues for a few seconds and then stops. It can't be heard in engine compartment when the hood is opened and also cannot be heard from underneath the vehicle. Any ideas???? Thanks!!

 

[Studmuffin]

I'm definitely no expert, but that's the exact same description I have for the sound in the Cobalt I drive, I know it needs a new Circulating Air Rotary Actuator for the AC system. Just my two cents.

 

[Hollister SSR]

No expert either. But it might be appropriate for someone familiar with the dreaded blend door actuator failure to listen to it.

 

[lgmII]

Thanks.....did the noise occur even when ac is off......and...….gotta show my ignorance...….is the blend door actuator what makes airflow go to dash vents or floor vents...….and thanks again, can almost always find info I need on this site

 

[oldfred]

Thanks.....did the noise occur even when ac is off......and...….gotta show my ignorance...….is the blend door actuator what makes airflow go to dash vents or floor vents...….and thanks again, can almost always find info I need on this site

DICKTATOR has posted info on this in the repair data base.
The knocking noise IS the actuator. Pretty cheap piece, except you have to take the dash apart to replace it.
JACK has the knock but if you turn on the center control at least one notch, it goes away.

.
The actuator has a slipped gear but NO HARM to just leave it.

 

[04 PurpleHaze]

Sounds like the blend door for HVAC is stuck or broken made out of plastic I had that happen to my 04 I was lucky and had bumper to bumper insurance so they covered it. Hopefully you can find some one to help you replace it as the dealer will charge you and arm and a leg, they have to take the dash apart to get to it.

 

[lgmII]

Thanks for the info folks.....really appreciate y'all!!!!!!

 

[Dicktator]

Do some reading on SSR How to Library:

https://onedrive.live.com/?id=3EF39D9F5ADCE5E5!853&cid=3EF39D9F5ADCE5E5

Look for BLOWER MOTOR.

I did not put "Blend Door" on SSR How to because it is an expensive repair and very time consuming. Tried it, 6 hours later, still not fixed.

Dicktator

1. Have to strip dash, upper, middle, lower and even then can't get to 6.5mm screws easily.
2. This is blend door for "inside" circulation or "outside" air. We duct taped door in position and pulled "plug" to Blend door.
3. This is actuator with broken plastic "tooth" on sprocket
4. This is where bolts are located to actuator, close to windshield on side of dash frame. GOOD LUCK!

 

[Jukebox2005]

Had the problem fixed last month. It is a major project, but there is a place here in Rockwall, TX that is willing to do it for less $ than anybody I found. Had all three actuators and the blend door replaced (mine was broken). It would be worth driving some distance if you wanted it fixed bad enough. Otherwise, just setting the A/C controls to Recirc would keep mine quiet before the repairs.

 

[nj6969]

I keep ours on Recirculate ALL THE TIME!! Why would you want to suck 100 degree outside air and push it thru the A/C coil trying to cool it?! Or 10 degree outside air trying to heat it!? Your house recirculates the inside air = Efficiency! Don't know WHY they give the option for outside air----unless you have a gas/flatulence >

 

[Jukebox2005]

I keep ours on Recirculate ALL THE TIME!! Why would you want to suck 100 degree outside air and push it thru the A/C coil trying to cool it?! Or 10 degree outside air trying to heat it!? Your house recirculates the inside air = Efficiency! Don't know WHY they give the option for outside air----unless you have a gas/flatulence >

Common sense might prevail here.