Euro city light- fogged

[timreid]

Just a few months ago I connected the Euro city light in my headlamps, a neat look. Today it was a rainy/humid day, had my city lights on, and I notice that Euro lens on the inside was fogged, has anybody notice if your Euro lamps do this? I thought maybe it was due to the heat of the 5w bulb/humid weather, and I'm a little concerned if the moisture on the inside lens could cause damage.
Thanks, enjoy your drive, timreid

[MTI]

Give the lens and the rear access hatch gasket/seals a check since it sounds like moisture getting into the lamp assembly.

[timreid]

Thanks MTI, you’re probably right, an answer I was kinda not wanting to hear. Just last week I had to replace my left lamp unit, a hawk dove into the lamp (must have thought it was prey). When I ordered a new unit, I replaced the lens on the right lamp. To replace the lens, I had to pull the unit out, so I was hoping it was something simpler to do, since both fogged.
Enjoy your drive, timreid

[bobbyv]

i believe that the Euro lamps are vented by design - there are small breather passages designed into the lamp assembly.

The rear access hatch seals are just to keep dust away.

from time to time, i also notice some moisture forming inside my lens, but the heat from the bulb dries it out eventually.

Just recently swapped out the headlamp rear access hatch from my kid bro's 190e (Euro) for the same reason.

The original hatch had a crappy gasket and the hatch did not seal very well.

We took a hatch off a spare headlamp unit, and there has been much less incident of fogging on that lens. The other lens doesn't fog at all. This leads me to believe that it is supposed to be a tight fit and that there are no vents...I could be wrong but it would seem logical...

The weather here in Singapore is VERY humid and I don't get any fogging at all on my headlamps (190e) so I could be right about the tight fit.

Good luck.

Azhari
Babybenz 1991 190e 1.8

Btw, on 190s here, I noticed that in headlamps with fogging problems, normally the paint on the reflector of the lamp peels.

My $0.02.

Azhari
Babybenz 1991 190e 1.8

[johan01]

One way to get rid of the fogging is to leave the cover off!

I believe you either seal it tight, or leave it open and let the moisture escape. Somewhere in the middle, and you get fog.

[timreid]

Concerning the back cover seal, to get a better seal, what would you recomend to coat the seal with. How about using silicone lube/grease or something like plumbers grease?

enjoy your drive, timreid

I would personally go for silicon lube.

Azhari
Babybenz 1991 190e 1.8

[Greg in Oz]

The headlamps are deliberately vented at the rear, although the vents are designed to prevent the entry of water, they are not hermetically sealed as many believe. Fogging usually suggests that a gasket is not sealing correctly.

[bobbyv]

i was wondering if one could apply an anti-misting treatment on the inside of the lens, then this would prevent or reduce fogging.

anyone know of such a product?

[MTI]

There is a product, Fog-X, by the makers of Rain-X, that prevents interior fogging, but I wonder if the product was ever meant for headlight lens application.

Just as aside, I just unboxed a pair of Bosch Euros for my W201 and didn't see any signs of "venting" on the assemblies. While I admit that the plastic housing probably does have seams or some sort of air circulation to vent the heat generated by the bulbs, vents are'nt really visible.

and, have euro light owners noticed a difference in the color of the euro orange side markers versus the US DOT ones? The euro corners seem darker orange.

[bobbyv]

my 201 Eurolamp is from Bosch.

the venthole is located on the removable back cover of the lamp. There is a hole on the inside of the back cover that finds its way into an external vertical rectangular shaft on the side of the back cover.

this means that it is *useless* to improve the seal of the back cover, using silicone or grease, if the objective is to avoid fogging. I believe that the seal is just for dust protection.

by the way, fogging can occur if it is very humid and moist air gets trapped inside, and then the temperature drops (e.g., the headlamp lens gets wet from the rain).

[MTI]

Just popped off the cover, and sure enough, there was the pencil eraser sized hole on the inside of cover in the corner. Dropped some water into the hole and it ran through the rectangular duct on the same side.