4SUMERZ

Anyone know what causes this to happen? Is it moisture or temperature difference between outside and inside lenses.
I just had the passenger side fog up, but the other side was OK.

I heated the outside of the lense with a hairdryer, and it cleared up.
Anyone else have this same thing happen?

Gearhead Jim

I've had it happen a few times, both sides at once but usually not very "heavy". I couldn't do a direct comparison but it seemed like there was still a reasonable amount of light getting through the condensation.

If yours is one side only, there is an access panel or plug at the rear of the light, somehow accessible from the wheel well. You might have one that is loose or missing.

Not much help, I know...

4SUMERZ

Thanks Jim. I'll check that out. Could be loose or missing and allowing moisture in the light assembly.
The fogging happened shortly after washing the car and then taking it for a short drive.

Garibaldi

I haven't got my manual close by, but I'm pretty sure (80%) that it states that condensation should be expected. That doesn't it's welcome, of course.

4SUMERZ

I went out to the garage, and the headlight was fogged up again, after being cleared yesterday and sat in the garage all night.
Now I know it's moisture getting in the assembly.
I checked the light bulb covers, and they were tight, but I removed them and put some silicone around the edges before putting them back on.

Worse case, is I have an ingress somewhere else around the assembly.
I'm not looking forward to removing the assembly to seal all the way around, but I will if I have to.

Thanks

Blazin383

It's typical and not a problem. I think the manual mentions it and they even talk about it on the DVD that came with my car .

old stingray

murf257

I've had this with other cars after a period of time. I was advised to take a drill with the smallest of drillbit and open a tiny hole at the bottom of the lense to allow any moisture build-up to escape. It worked for me on other brands!!

Mad*Max

I don't think it is supposed to be air-tight, I haven't had this happen on my C6 but have on another car or two.

Knob Jockey

Here's a pic of the driver's side headlight assembly out of the car.

Note the 2 white tubes, they are vents.

The assembly is not sealed and this is also how bugs/spiders get inside.

Condensation is 'normal' and can be evaporated just by leaving the car out in the sun or using a hair dryer.

USA1 427

Mine's been foggy since day 1.

RLSebring

If you hate the fogging now you'll really hate the cloudiness later... The condensation will usually have some dust mixed in and when the water evaporates it leaves the dust behind and after a while if you fog on a regular basis you'll get that cloudy obscure look on the inside of the lens.

AZCE

It sounds like your headlights are sealed very well and air/moisture is getting in them.

Gearhead Jim

Call me a coward, but the "sunlight" method sounds a lot safer.
Even if we don't see the sun around here for months at a time...

pokerpro

I think I'll take a pass at that one.

4SUMERZ

YUK!!! I'll check to see if I'm getting moisture because of a seal etc. I know that the 2 vents are supposed help remove moisture, but I believe none should be there to begin with.
I did put some silicone around the rubber cups, and a bit on the low beam bulb, so I'm hoping that will work.
If it doesn't, then I'll have to try something else.
I won't be drilling any holes on the bottom of the assembly.
Have you had an issues with the lights that you do as far as fogging up?

owc6

I'm pretty sure those white tubes are one-way vents. It would be counter-productive to drill holes to allow moisture to "escape". They would just allow more moisture (and grime) an inroad. The key is to make sure the temp inside the fixture is higher than outside so that it will expel the excess pressure and any moisture with it. Usually driving with the lights on will accomplish this.

A hair dryer will not hurt them. I've used a heat gun on them (gingerly) to take a black-out set off the fog lights and it didn't hurt them.

RLSebring

The lights will still behave just like they did before I did anything to them. Condensation is considered normal by GM. Pretty much environmental condition. If the conditions are right you'll fog up which is generally colder inside the light than the outside temp.

Mine will fog up one time each year and it occurs at a car show on the beach in September. Never fails to happen and I catch a lot of ribbing that mine, of all lights, fog up.

4SUMERZ

Thank You so much for all the replies. I'm feeling better, knowing that this happens occasionally. As long as it doesn't become a common occurance, then I'll be happier

Flh Den

Thank you to everyone who posted on this subject. I had the condensation problem once and it cleared up on it's own and has never happened again. Now I know how and why if it ever does occur again.