Got my 2004 stilo 3 days ago. Was driving back home from work today passing a smelly factory i switched recirculation button on. After switching it off loud noise was present in dashboard area it sounds like actuator is moving back and forth rapidly. Or something is stuck and its clicking rapidly. If i turn on recirculation and light comes on the sound goes away once i turn it off and light goes off it starts clicking again. I switched engine off and on and sound went away with recirculation off. But if i turn recirculation on and off sound goes on again. What could be the cause of that? Thank you in advance!

The recirculation button closes a flap on the heater matrix. The flap operates via a skinny nylon cog.

I suspect the cog is trying to open or close the flap but it's tight or jammed. The clicked will be the teeth jumping over each other.

If you remove the cover on the side of the transmission cover and stick your head in there, you'll be able to track down the flap. I think it's under the passenger side cover rather than the driver's side but I might be wrong.

Make sure the flap moves freely by hand and then press the button to see what's happening when the car tries to do it.


Ralf S.

Thank you very much for information to where should i start my journey .

So i got access to it and i can see that servo motor with flap. It is struggling to move in either direction. When recirculation is off the flap is sealed is that correct position? I took picture but can't upload it :/. And to fix it i would neeed to replace servo motor? And to gain acces to remove servo i would need to remove dashboard? If sealed flap is how it should be then im just not gonna touch recirculation again

I'm not 100% sure.. but if the hole covered by the flap leads to the fresh air intake, then theoretically the flap should be open when re-circ is "Off"... so that when the re-circulation button is pressed, the flap would close and therefore stop fresh air entering the car

Are you sure the actuator is dead? Try giving the whole thing a spray of WD40 to see if you can loosen it up with some physical assistance at the same time the button is operating it. If you can move it through Open-Close a few times without breaking anything brittle, that might help the actuator to free off, if it's stuck.

I don't know but it's likely that to replace the actuator you might need a very small pixie to do it, or you will have to remove the heater matrix. On the other hand... a fit lad could probably manage it over a weekend..


Ralf S.

It is moving sometimes if i help with hand. So far i figured out that potentiometer inside actuator is dirty and thats why its clicking because it doesnt know in which position flap is. The part im concerned about is if flap position. I would need to reverse direction somehow if its wrong. And unplug that actuator hoping i will not get warnings on dash

my actuator stopped working a couple of years back and it stuck on re-circulation.
I'm not a novice at these things but decided replacing the actuator was not an in-situ job, and I wasn't planning on taking the dash apart. I jammed something in the flap, to keep it on fresh-air in (else you fog up).
From memory, I think the flap looks closed when set to fresh air in, but not 100% sure.