Guys, don't know what is happening here. Didn't have this in the past 5 months. Then changed to the new osram bulbs and now I get the foggy on the bottom half of the lens.

I thought that it was taking the light assembly and bringing it into a warm house to change the bulb which introduced humid air in. So, I took it apart again, and left it in the house for a couple hours. Took of the back housing and let it dry out over night. I did leave the bulbs in though as it didn't appear it was sealed beyond the back housing.

Installed and I still have foggy but a bit worse. Mind you the weather has gotten worse(wet) over the past week though. Any help would be appreciated.

 

I haven't messed with the headlight assembly on a 911, but in previous cars where I ran into this problem it was always a gasket / seal issue. You might want to replace the gaskets and try again. They tend to lose their seal as they age pretty easily.

 

There's only one seal which is the back housing unit. I guess I can see if porsche sells that as a replacement item. Such a pain over changing a headlight bulb.

 

Another thought. My real curiosity is. I noticed there is a venting tube in the assembly. So it must mean that the unit isn't sealed from an air exchange perspective. There should be a difference between water leaking issues and condensation. Once the headlight cools down, the fog disappears (albeit, overnight) so what am I actually drying out then?

Isn't the vent tube allowing air back in? If the air is moist and cold outside. Wouldn't I have the problem again?

 

Unless the vent just stopped working, you've most likely had some condensation before but only noticed now since you are more aware of the assembly after changing the bulb. But having said that, I've had my housings open multiple times to change bulbs and never have experienced condensation.

 

Thanks for the input. I can't see how both vents would just stop working and yes, I admit, I am the OCD type of car owner :-). So I would have notice the condensation before. I can't see how the design of the unit would allow for such an issue when the unit was opened just change the bulb? Otherwise all owners in a wet damp climate would have the same issues. I read that other owners and porsche have put dessciant packs in the housing to help absorb?

Anyhow, I think it's a bigger issue for Canadians cars, as our laws force dealers to program the system to keep the lights on. Most manufacturers do this by powering down the highbeams to 30% power. But in the 997.1, the daytime running lights are achieved by the headlights, thus the headlights are on all the time.

You would think with 30 minutes of runtime to heat up the unit hot enough for the moist air inside to escape out of the vent? Is that what the vents are for?

 

Well as I mentioned I live in a humid climate with extreme temp changes and I have the DRL headlamps on all the time and no condensation issues. Now you're going to make me look closer. 997.1 TT.

 

Sorry! i just got off the phone with the dealer and they said it was normal but as long as it disappears in a couple of hours. They said its an issue if the condensation stays which would mean a crack in the unit somewhere?

I was reading in the forums that people are using a Desicant material to place inside the headlight unit? I was wondering were and if i should even try