Strange sound from CL9

[morgs202]

So, tried searching to see if this had been posted before but with no luck. For a couple of months now my 2005 cl9 has been making this really odd sound that I think might be associated with the climate control. It's a bit of a hard noise to describe but the best I can come up with is that squeek sound you might hear when polishing a window. It seems to happen when then clunate control changes temp or fan speed? Anyone else heard of or this issue before?

Cheers

Morgan

[peteyyyy]

Is it like a 'whoop' noise?

[morgs202]

That's the one! Pretty well perfect description

[aaronng]

There are 2 types of sounds associated with AC. One is a whoop sound, which is related to the thermal expansion valve. It is loud and can be heard from outside the car. The other is a creak/squeak sound, which is the air vent direction changing. You can only hear this from inside the car. Someone standing outside won't be able to hear it. You can test the second by setting the AC to blow out of the face vents manually. If you then never hear the sound again while driving around, then it is the vent. Just live with it. If you still get the sound, then it is the whoop sound from the thermal expansion valve, which you might want to replace if it gets irritating.

[morgs202]

Hey, thanks for that! Definitely a whooping sound a pretty loud too, so I'd say its the valve. I'll look at getting it replaced, thanks heaps for the info!