W212 Thermotronic - issue with rear?

[ptruman]

Lo all

Merc have had my W212 today and changed the turbo seals due to a small oil leak.

I've noticed this afternoon that while the front vents are all merrily pumping out chilly air, the rear zone central vents are pumping out hot air, the right B pillar vent and under driver seat vent are also pumping out hot air, but the left B pillar and under passenger seat vent are pumping out cold air.

Any clues? Have they knocked off a hose? Is the aircon buggered?

 

[Mr Filipov]

Are you sure yours isnt a tri zone climate control? One for each person in the front and a third zone for the rear.

 

[ptruman]

It is 3 zone, but the vents are acting as described.
Front is fine.
Left B pillar and under left seat are NOT producing the same as the right B pillar or under seat, or central rear vents.

 

[MatthewCDN]

It is 3 zone, but the vents are acting as described.
Front is fine.
Left B pillar and under left seat are NOT producing the same as the right B pillar or under seat, or central rear vents.

I am having the same problem with my W212 E350. Did you ever figure out what it was?

 

[ptruman]

Nope - I'm told there is a diverter valve (or similar) which needs changing but may be in a stupid place. I've basically just closed the rear vents so any rear passengers (i.e. small person!) isn't cooked. Front seems to be powerful enough to keep everyone cool.

 

[AndrewOl]

Would be worth checking the refrigerant gas pressure. Similar symptoms with my 2006 GL were cured by a gas recharge.

 

[ptruman]

Could do but it's icey cold at the front, I'd have thought if the gas was low it wouldn't even get that?