C205 (or W205) Foggy Headlamps - Replacing Silica Gel de-moisturizer pack ?

[Uky]

Greetings Forum.

The not so new C205 purchased some time ago forms fog/moisture inside the head lamps every now and then.
There is no recall for this problem. I have approached MB agent regarding possible GW action. No answer so I guess I will have to replace the de-moisturizer packs myself.
Removing the headlamps is cumbersome but it can be done on a sunny day, then opening the rear lid - wherever it is located - and replace the silica gel pack.

On the internet, there is at least one quick video describing this procedure. In the workshop, the vehicle is to be running at idle for 1 hour with the headlamps on
so that the de-moisturization process will run its course. Are there really no diagnostic procedure that turns on the lights ina workshop environment without
having to have the car at idle? This seems extremely odd - not to mention the exhaust gases.

Anyone replaced the packs on his own driveway?

 

[liamt]

I've never heard of this 'de-moisturization process' but all the Mercs I've owned have had fogged up headlights which I believe is perfectly normal due to them being vented and not completely sealed. As long as it isn't swimming with water inside then it should be fine. It normally occurs when there has been a change in temperature.

 

[whitenemesis]

There is a WIS doc regarding headlamp misting, stating it is not a warranty issue and any misting will disappear when the lamps are on for a while.
As above, as long as there isn't a puddle in the unit there's no 'fault'
Any silica gel pack in the unit would be exhausted within hours and I can't think it would be a factory inserted pack?

 

[Uky]

I got information regarding this problem from a friend.

Apart from the silica gel-packs, there is also a membrane that should be replaced.
The membrane should allow over pressure to get out but not moisture to get in.

Total parts cost for replacing the gel-packs for each headlamp is about 70 Euros.