S211 - any well-known air con problems ?

[flying banana]

four questions regarding ventilation/air con on my newly acquired 2009 s211 e class estate.

firstly - noticed the other day that even when set fully cold, the air con doesn't blow icy cold. It was pretty cool outside but would have thought I'd still have chilly air through the vents...or is there some intelligence in the system that takes external ambient temps into account?

secondly - I may be imagining it buying full auto mode my legs seem to be cooler than the cabin - can't feel any drafts or obvious sources of cold air, is this normal of do I have weird thighs?

thirdly - with the fan at max and the controls set to blow air only out of the footwell, the flow of air doesn't seem 'gale force' and there is still air coming from the dash vents. is this normal?

fourthly - with everything in auto and the cabin temp stable, and the dash vents open, I can hear a faint but noticeable hissing noise. I would have expected a merc ventilation system to be virtually silent but maybe I'm expecting too much?

probably nothing to worry about but it's my first merc so I have no frame of reference.

thanks in advance for any light than can be shed

cheers, Tony

 

[cws196]

Lack of icy-cold air combined with hissing sounds to me, like the a/c is low on gas. I was to the hissing is caused by compressor having to work harder due to lower gas content. Get it checked out-in my case with similar symptoms, the condenser had a tiny split.

 

[BlackC55]

+1. Its low on gas. You probably have a leak. 9/10 its the condenser.

 

[flying banana]

Thanks - will get that checked out. is this the kind of thing that would show up on STAR?

thanks again

Tony

 

[cws196]

This is one of the few times where I'd think plugging STAR in won't really tell you much other than low gas-personally I'd save the money and just go to an air-con specialist and ask them to remove the remaining gas and then add dye to the system/re-gas and look for any signs of dye seeping out (most dyes show up under UV light). As per the general consensus, I bet almost certainly your condenser has split and that's quite an easy fix as far as air-con systems go.

 

[flying banana]

Ta

 

[flying banana]

On the other "issues" - should I expect air to always come out of the dash vents regardless of where the diverted controls are set (even on the max screen demist setting?) or is it likely that some motorised ducting valve is stuck/malfunctioning?

cheers folks