W201 Euro headlight water intrustion
 

I had to park my 190 outside for a few days, under a double cover, due to work being done on the house, and it's been raining a lot in SoCal.

I first noticed condensation inside the LH lens, and the next day condensation was under the RH lens, and there appeared to be actual liquid water on the bottom of the LH lens.

My driveway slopes down and the car was backed in, so water runs down the fender gutters and spills out behind the lamp housings, but not that much. I couldn't find any obvious sources of the leaks.

I reversed the car so it's parked upslope. That might help, but my question is if anyone else has experienced this and found a solution.

Duke

As you may already know, there are different kinds of moisture and how it
might get inside the headlamp housing. condensation or direct. if it is via
condensation, I think ventilation is important ... which can be the different
approach to what many people think of, which is to apply more sealant.

with direct entry, you'll need to find the seam that has been compromised in
order to patch. the simplistic, ham fisted approach can be effective which is to
apply RTV butyl around the perimeter of the headlight, i.e. along the seam
between the outer lens and the headlight shell.

without having the benefit of inspecting your headlight, I would float the
possibility that the (normally gray) butyl sealant may have been compromised
especially with aftermarket headlights so inspect the seams carefully.

My 16v had this issue. As I recall, there was a rubber seal that went between the glass lens and plastic housing. I searched but could not find a replacement.

I ended up getting some clear silicon caulk, running a bead in the groove of the the plastic housing, reattaching the lens with the metal clips and viola. No more leaks. this worked with out issue for several years before I got rid of the car.

Also, check the seals on the doors behind the lights. They might be damaged, MB dealer did have new doors and they were not that expensive.

Which Euro lights? I have Depo's, and I've been struggling with this issue on one light for a very long time. I think it's somehow coming in around the door where you change the bulb, but I've never been able to catch it.

I bought them back in 1984 for installation on my 2.3, and then transferred them to my '88 2.6. As far as I know they are OE W201 Mercedes assemblies, not aftermarket.

Thanks for the replies. I'll check the bulb door seals as that can be done on the car, but if that doesn't work, I'll have to remove the assemblies and reseal the lens.

Duke

Mine came with the car from the factory but I would imagine the configuration would be similar.

You can replace this gasket with foam rubber weatherstripping.