W203 air con high pitched whistling

[cplnoonoo]

When using the heater on auto setting and using it to warm up the car it seems to be emitting a high pitched whistle kind of like an old kettle boiling on the hob.

Its quite irritating given the frequency of the whistle as it goes right through you. Does anybody have any ideas as to what this could be?

@Mods: sorry posted this in engine by mistake. Could someone shift it over to interior please?

 

[whitenemesis]

Perhaps the flaps need resetting? I had something similar just recently, dealer used STAR to resync the flaps and now all is much quieter.

You can try resetting the flaps yourself by holding the Recirc and Demiss button for >5sec (ignition on, engine off) the aircon should go through various operations (the Leds will flash) may take approx 1min. When finished switch ignition off and on again and start engine. Hopefully all will be well. STAR will do a more thorough job though.

 

[BlackC55]

It means the AC gas is low and you may have a leak. It is an irritating noise and it come from the centre vent area.

 

[whitenemesis]

It means the AC gas is low and you may have a leak. It is an irritating noise and it come from the centre vent area.

Whitenemesis vacates the "centre vent area" and goes and stands in the corner.

 

[Satch]

I had that for a while and it drove me nuts.

Eventually I traced to a most complex cause with a hugely difficult fix: one of the rear vents was not quite shut

 

[crankiejohn]

my 203 was doing the same,got it regassed at kwick fit and the noise has gone

 

[BlackC55]

Make sure the leak is fixed. The gas has to go somewhere.

 

[cplnoonoo]

How can i tell if it has a leak apart from the whistling noise?

Should i try doing the flap reset as suggested by whitenemesis first?

 

[kwakdonut]

Can't do any harm - always go for the cheapest option first in this case!

 

[cplnoonoo]

Ill give that a shot tonight when i finish work then.

If it still gives me problems where can i look to find any evidence of leaks etc?

Im off work tomorrow for a long weekend so iv got plenty time to go looking for leaks and getting it sorted. Think i might even get my winter boots fitted onto the motor this weekend aswell as i had to scrape my window for the first time yesterday morning lol.

 

[cplnoonoo]

Well i tried the reset thing and it did its fancy light show and moved through all the options but it hasnt seemed to work. If anything its getting slightly worse.

Is this gona be something thats going to cost me to find out what it is plus repairs?

 

[whitenemesis]

As Olly suggests, get it regassed and see if that cures it.

 

[cplnoonoo]

How much would that set me back and does it matter where i get it done eg local garage or dealer?

 

[camerontyler]

Don't bother wasting your time & money just getting it regassed, I too have had the same problem with my 203.

As BlackC55 (Olly) has already said, the gas has to go somewhere, i.e. it's had to escape from somewhere to need re-gassed.

Mine was a simple broken o-ring on the front left connection (technical) when looking at the engine bay.

I don't know how much it costs to fix because I used the sale of goods act to get the dealer to fix it. They called in a mobile air-con engineer, he found the fault within 2 minutes, replaced the o-ring, tested for leaks then re-gassed. Took less than an hour.
I then nipped down the road from the dealers to the local auto-electricians, he plugged into my ecu with a multi-car-machine, removed the fault in 20 seconds, job done.

In conclusion, goto yell.com, search for a mobile aircon specialist in your area, phone a few and get quotes, choose one, set a date & time, goto the cash machine & put the kettle on.
Once the jobs done, get back on yell.com, find a local auto-sparky that has a multi that works on Merc or a STAR. Get them to remove the fault, job done.

If your car is hooked up to STAR kindly request they remove 'UK mode' from your ecu, this will allow you to change the currently unchangeable KPH in the bottom left of your screen to MPH.

 

[rolandbarnes981]

Really Annoying This Whistle

All,

Thanks for supplying all the information in this thread so far.

I've had my 2006 CLK 320CDI for a few months now and LOVE IT TO BITS - apart from a few minor niggles.....

This whistling when the air con is on is one of them and I'm pretty sure it comes from the drivers side window vent - turn the air con off and it stops.
Strangely too when you switch the AC off it belts out even colder air for a few minutes ????

So any advice on this welcomed - I have tried the demis & recirc option just now but it didn't seem to work as no flashing lights were seen but "some" noise activity heard with vents.......it's still whistling with A/C on.

I have seen posts mentioning leaves etc stuck inside the AC passages - not sure where to look for this ?

The other really strange thing that I've noticed from day one is an audible and annoying hum within the car when the ignition is off - listening to the vents earlier as above I think the hum/buzz is coming from the console above your head with reading lights and phone speaker - any advice on what this might be please ?

Thanks in advance - so love the car but niggles are annoying me :-(

Cheers,

Roland