Knocking Behind A/C Vents

[bkm2009]

Howdy All,

Im hoping someone on here can help me out.

I have been driving my misses Omega lately, and when you start the car, there is a few consecutive 'knocks'' coming from i guess the A/C vents or radio screen.

the knocking only lasts for about 2 seconds, & then stops, and you dont hear it again until the next time the car is started.

Is there anyone here that knows what this sound may be?

 

[Head_is]

Im guessing its the little motor which controls the Air Con. Had same thing happen in a new ranger, But the omega doesn't have climate control does it... Because when I had mine set to like 22 degrees (climate control) it would knock on and off when it was changing stuff around. But since the omega doesn't have climate control I'm guessing that it is doing it on startup and shutdown which is what mine also did.

So I'd still take it to a dealer but I dare say that it is the aircon control motor if that make sense? It's not the actual motor it's just a little one that selects things behind the dash I think.

This is how I described my noise... It is a little leprechaun making shoes inside my dash.... lol

 

[stirringaxe]

Try doing a HVAC door relearn.
Ignition on - but engine off, press and hold the rear demister button till you hear all the actuators moving.
They are fairly quiet so close all the doors and windows so you can hear them working.
That might fix your problem.
If not the plastic cogs on the door actuators can wear out & need replacing, may be that.

Good luck

 

[Head_is]

Stirring sounds like he knows more about it and that's probably what it is

 

[wedgee]

Nah my money is on the aircon actuator.... mine needed replacement after about 12 months.
Common problem apparantly :/

 

[cds]

Nah my money is on the aircon actuator.... mine needed replacement after about 12 months.
Common problem apparantly :/

+1 for the Actuator... Had exact problem after 18 month VE Calais 07. Learninging does nothing.

 

[RiCeY]

Yep fairly common, the gears in one of the vent door actuators strips and makes the clicking noise you hear.

It's usually the top one on the drivers side which is a bit of a bitch to get on and off due to not much room to access one of the screws.

Actuators themselves are fairly cheap.

 

[Troyziee]

Just had two of my HVAC actuators replaced last friday, after the same clicking noise.

All good clicking noise is gone, however there is literally NO fan speed anymore...
I had the aircon on yesterday and noticed i couldnt feel a thing blowing toward me, so cranked the fan speed up, and still nothing. Could hear the fan working away, so put my hand up to the front windscreen/dimister vent, and that was cranking cold air, turned on the rear vents, and they were cranking cold air, but the entire front dash/footwell vents were literally blowing nothing!! I could have held a feather upto the vents at full fan speed, and the feather not move, and thats not an exaggeration.

Was going to head to holden this arovo, but got stuck at work, will head up tomorrow, however, are they going to bullshit me, or is there anything i can try at home??

 

[RiCeY]

Either they replaced the wrong actuator or they didnt seat the control arm for the vent into the actuator properly.

 

[Troyziee]

They replaced two actuators. Is setting that control arm something I can do worst case?