W219 CLS cabin air/air con system

[MARtinClS]

Hi all,

Wonder if you can advise -

I have a (pretty constant) whine from behind the centre of the dashboard when the cabin air is on (no difference if air con is activated or not). It also doesn’t really vary too much regardless of fan speed.

If I switch the system off completely it stops. It’s not coming from beneath the glove box so I don’t think it’s the blower motor.

Are there any other moving parts in the system? I sort of thought it was basically the blower motor and a bunch of ducting but maybe I’m wrong..

Any ideas?

Cheers,

Martin

 

[dry run]

That would annoy the hell out of me!!! I hope you get it sorted

 

[Wighty]

Hi all,

Wonder if you can advise -

I have a (pretty constant) whine from behind the centre of the dashboard when the cabin air is on (no difference if air con is activated or not). It also doesn’t really vary too much regardless of fan speed.

If I switch the system off completely it stops. It’s not coming from beneath the glove box so I don’t think it’s the blower motor.

Are there any other moving parts in the system? I sort of thought it was basically the blower motor and a bunch of ducting but maybe I’m wrong..

Any ideas?

Cheers,

Martin

If you remove the pollen filter does it make a difference ?
It might be clogged up

 

[mioba]

Hi all,

Wonder if you can advise -

I have a (pretty constant) whine from behind the centre of the dashboard when the cabin air is on (no difference if air con is activated or not). It also doesn’t really vary too much regardless of fan speed.

If I switch the system off completely it stops. It’s not coming from beneath the glove box so I don’t think it’s the blower motor.

Are there any other moving parts in the system? I sort of thought it was basically the blower motor and a bunch of ducting but maybe I’m wrong..

Any ideas?

Cheers,

Martin

when was the last gas recharge, the gas contains lube. And check and replace pollen filters you may well have 2 separate sets.

 

[Larkone]

Stepper motor on the vents perhaps?

 

[MARtinClS]

Pollen filters changed 6 months/1.5k miles ago and air con gas was recharged 2 weeks ago.

I would say, weirdly, the noise disappeared for a week or so after the recharge and has slowly come back. The system is holding pressure though…

 

[MARtinClS]

Stepper motor on the vents perhaps?

Possibly this, would make sense. Do you know if this is accessible/reachable from the mid-dash air vents? I’m thinking about spraying some kind of lubricant or something.. odourless of course

 

[Vic Small]

I have a similar issue, mine is more a 'groan' than a whine and its getting louder with time (I'm on 220,000 miles, 2010 CLS GE) It stops when you press 'off' button, is unchanged if you switch the aircon off but I have always assumed its the compressor/condensor as mine sounds more lie its coming from the engine bay. I've not investigated cos assumed it would be expensive and I'm just about to say goodbye to my CLS (full story here: Beginning and End of my CLS ) This probably doesn't help at all but worth listen under the bonnet/getting a garage to have a listen, good luck

 

[MARtinClS]

I have a similar issue, mine is more a 'groan' than a whine and its getting louder with time (I'm on 220,000 miles, 2010 CLS GE) It stops when you press 'off' button, is unchanged if you switch the aircon off but I have always assumed its the compressor/condensor as mine sounds more lie its coming from the engine bay. I've not investigated cos assumed it would be expensive and I'm just about to say goodbye to my CLS (full story here: Beginning and End of my CLS ) This probably doesn't help at all but worth listen under the bonnet/getting a garage to have a listen, good luck

Turns out the cause of mine seems to have been low air con gas. I had it regassed and the noise disappeared.

I also had a leak from the condensor; if the gas was at full capacity then I had no noise - anything significantly below full would create this intermittent whistle.

The other thing to note is that, after investigation, it was actually coming from the blower motor area beneath the glove box; I guess the acoustics of the ducting behind the dashboard moved/amplified the sound so it sounded like it was coming from behind the centre of the dash.

Either way; a new condensor and a gas recharge and it’s back to silence!