Severe condensation

[the flying scot]

I had a problem with severe condensation in the car so bad thet I had to switch on the windscreen boost heater to be able to see out.
Found the problem while fixing my wiper moter...the interior air recycle flap was stuck closed (that's the one on the dash with the car outline and a arrow indicating air flow). If it was open pressing the button would close it and the light would indicate it was closed.
Switching it off? Nothing, it stayed closed.
WD40 on the push bar fixed that when I came to changing the cabin filters.
But lots of screws and panels just to get one squirt of oil in the right place!

 

[coalville126]

Had a similar issue when I first got my W210. It was a lightly used car prior to my ownership and would steam up terribly unless the aircon was on when driving.

There was also what I can only describe as a stale smell in the cabin. This led me to replace both the pollen & charcoal filters and like the previous post, I found the fresh air damper stuck closed while replacing the upper filters. Exercised the damper a few times by actuating the recycle button and it's working fine.

With fresh air now entering the car, the smelt fresh and no longer required a/c to keep the windows clear.

 

[Southy1978]

W176 A classes suffer from the vent flaps leaking behind the rear bumper, very common issue. Also poor seam seals in various places around the car like the A pillar and roof.