[Roi354]

Woke up to loads of condensation in one headlight today. Had a quick look and it doesn't appear I can get in there easily to dry it out and reseal any covers.
Any tips?

2017 G31 if it matters.

[NVRfollo]

Put a hairdryer to it.

[eric_gm]

Condensation inside headlights, even in brand new cars is not abnormal and happens under certain conditions. If there is a large temperature delta between the outside and inside of the housing (example: winter temps outside and HID or LED bulbs heating up the inside, or even the engine heat transferring to the back of the housing). Think of it as leaving a glass full of ice on the table for a while, condensation will build up around the glass.

Most headlights are not 100% sealed and have vents. Those vents are supposed to prevent condensation, but sometimes air moisture finds its way in. Just inspect the housings for any signs of damage, leave the car in a dryer place or use a hairdryer as suggested. If it doesn't occur all too often and there is no visible damage, it's normal.

https://cbsparts.ca/admin/bulletins/...%202015....pdf

[Chappers 71]

I can get a bit of condensation in the front lights on occasion when I wash it, no big deal drys out quickly

[430Scud]

Both of my headlights occasionally get condensation and I asked the dealer about it...they claimed mine was not bad enough to do anything about. I noticed the brand new 5 series loaners I would get were often much worse...and these cars had less than 500 miles on them. My car is a 2018 and these were 2021 and 2022s.

[Roi354]

Thanks for the replies.
I've had condensation in a headlight on another car and everything inside rusted to the point where contacts began failing and needed to be completely replaced. I doubt very much whether this should be considered normal, regardless of if you've seen it on others or not.
Fortunately after 4hrs of driving yesterday it appears to have cleared up, but I still say they shouldn't do it.

[pault1980]

As absurd as it sounds, BMW actually have an air dryer built into a lot of their headlights- I havent looked at a G30 headlight closely to know if they have it but the tech info suggests they do.

[LogicalApex]

Originally Posted by pault1980

As absurd as it sounds, BMW actually have an air dryer built into a lot of their headlights- I havent looked at a G30 headlight closely to know if they have it but the tech info suggests they do.

Thanks that was a good read. It prompted me to check the G30 details. Although it lacks a dryer of that type it does have 1 or 2 active fans depending on headlight type. That makes sense as LEDs get extremely hot. So BMW likely manages it via controlling LED headlight temperature in the G30 for drying.

But that likely would allow some minor condensation when the headlight isn’t running.

[Roi354]

Originally Posted by pault1980

As absurd as it sounds, BMW actually have an air dryer built into a lot of their headlights- I havent looked at a G30 headlight closely to know if they have it but the tech info suggests they do.

That's very interesting. So as I read it (assuming I have these in my headlights), if I drive for 35 minutes each heater/fan would have completed the cycle of heating and blowing to evaporate and expel moisture.
In theory after a few days of doing this it could completely dry out even a stubbornly damp unit. Cool!

[LogicalApex]

Originally Posted by Roi354

That's very interesting. So as I read it (assuming I have these in my headlights), if I drive for 35 minutes each heater/fan would have completed the cycle of heating and blowing to evaporate and expel moisture.
In theory after a few days of doing this it could completely dry out even a stubbornly damp unit. Cool!

G30 lacks heaters and only has fans, but that makes sense due to how hot LEDs get. So it just needs to vent or cool them down and they’ll heat up on their own.