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Eddy Matthews

Headlight condensation - cheap fix!

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As lots of BMW's seem to have, my car also suffered from the dreaded condensation inside the headlights making them less than useless!

The cure was easy - Drill a couple of 1/8" (3mm) holes in the top of each light unit, so the holes are hidden by the bonnet when it's closed. Sit a small fan heater in front of each light for about an hour or so to get them nice and warm and drive off the condensation, and voilla no more water inside the headlight!

The holes allow any future condensation to exit the lights, and even though we've had very misty weather and rain since I did the job two weeks ago, there is no sign of any water!

Regards

Eddy

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interesting idea..

any pics of the actual light and location of the holes??

I was worried that rain water etc..would enter the light as it goes down the "gutters" along the bonnet / wing and out over the lights??

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What does the round cap/bung clear round thing at the top in each headlight actually do?

If you take them off, you will see each has a little lever, whch you can switch to adjust the aim of your headlights from UK to European

edit: you beat me to it stelmo :D

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Since I used to own a Toyota Estima (import) with plastic headlights, they had exactly the same problem - Drilling a couple of small holes at the top is the common fix for them, and it's certainly worked on the BMW lights just the same....

Drilling holes at the bottom doesn't work - As the condensation heats up due to the headlights being on, or just with sunlight on the car, the water turns to vapour and RISES.... Normal physics, heat rises, so the holes have to be at the highest point. ;)

I have to admit that my BMW headlights are aftermarket units, not original BMW, but none the less the "cure" has worked, and saved me a LOT of money! :D

Photos to come tomorrow....

Eddy

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so you can get ur fingers in there to flip it to LHD or RHD

Oh right,

Well i had condensation in my drivers headlight so i took it off the car after finding a guide on the web. Split the lens from the headlight, kitchen rolled the wet out , left in airing cupboard for a hour, vacumed the indicator lens hole (yes really, most of the moisture vanished from the indicator) cleaned both the breather holes and filters and sealed the bung/cap from the inside using high temp tape (that i 'borrowed' from work) blasted the tape with a hairdryer for 30secs to seal it, before recliping the lens to the light wiped the inside of the lens with anti-fog..

Put back on the car and 3 days later its clear and i have had rain all day yesturday and warm today..

Wish now now i'd done before and after pics !! DOH!

Guv

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my passenger side light mists up quite badly ..not to sure I want to have a try at the previous owner when fitting the halo rings ,did so without leaving any removable joints..so any fix for me would need to be on the car .. :evil:

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Drill a couple of 1/8" (3mm) holes in the top of each light unit

 

Tried that, didn't work.

 

i suggested that dropping silica gel sachets in the lamp casing would help.

 

Tried that too, didn't work.

 

I thought i'd solve it by buying some brand new light units, fitted them about 6 months ago and guess what, yes, they have condensation in them.

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Heck guys !     Just drive for a few days with your headlights on and slowly it WILL go away.   Did it with my recently purchased BMW and several Omega's, worked every time.

 

As long as cars are used fairly regular its VERY unlikely the problem will come back..Just be patient !

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I kind of agree, never had an issue with condensation, I tend to drive with my headlights on most of the time (got auto-lights, they work really well actually and do tend to be on more than off).

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Tried all of the above, small holes, and drivin gwith lights on and its never cured it - After everythign a replacemetn set of lights has been the only fix thats worked! Cost £45 in total for both from different places :)

 

be careful with heating to get condensation out though!

 

_MG_0889.jpg

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Had the same problem on the missus' 535. I took the glass cover off the UK/EU beam adjuster, parked the car facing facing the sun for a few hrs and the condensation disappeared from the headlights. Still a bit left in the indicator lens tho', and this might cause the unit to mist up again. I like the tip about vacuuming the indicator bulb; I'll try that if the condensation comes back.

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Here is what I've just done with mine, having first disassembled, cleaned, then thoroughly dried all internal surfaces. 

 

 

These are 3mm holes drilled along the bottom edge of the housing. This allows water out from the light section behind the glass lenses.

 

post-45976-0-50928600-1364996132.jpg

 

post-45976-0-45264200-1364996158.jpg

 

Here is a hole in the outer lower corner of the indicator, this will allow water out of there where it can become trapped between the orange (or maybe clear in your case) indicator lens and the outer glass cover. The other end of the light unit has a built in drain hole already at the extreme lower inboard corner, so now any trapped water at least has a way out at the bottom in a couple of places.

 

post-45976-0-36000600-1364996376.jpg

 

Here I've drilled holes at the corners of the main headlight black plastic shroud, this should allow cross ventilation of air into both fore & aft sections of the headlight. Not shown, I've drilled a few holes from behind the reflectors quite low down, again to allow ventilation in.

 

post-45976-0-74044800-1364996396.jpg

 

Not shown here, I've also lifted the rubber seal from across the top and down the edge of the indicator, given it a good clean and degrease, applied clear silicone sealant all along the edge where the clear outer cover meets the black plastic, then re-stuck the seals back down using the same silicone mastic material. 

 

In this overview photo, I have indicated the position of the holes. Maybe there are too many, but while it was open I took the chance to vent any and all areas that I had found condensation inside.

 

post-45976-0-92600600-1364997337.jpg

 

 

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Good work, and will be interested to see if it has worked on yours.  I didn't drill that many holes but tried a simular fix I'd read before on mine but still did not work!! :(

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Lightweight lights, saving weight for a faster 0-60 time ;) 

 

I would expect that will help, I just blasted a hairdryer into mine for about an hour and left them in the airing cupboard for a week. Never had a problem with them since.

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Here is what I've just done with mine, having first disassembled, cleaned, then thoroughly dried all internal surfaces. 

 

MP3, with the weather being, er, changeable at this time of year, and given that you did this in April, have your mods to the lights worked, long-term?

 

I'd be keen to know, because both mine are misting up at the moment. :(

 

I'll go down the drying and drilling route if there's a fair chance of success. :lol:

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Morgan, nice to hear from you  :-P

 

To answer your question, yes it did after a little fettling. I hadn't let the RTV sealant dry out 100% before refitting, and I did get some minor misting, but upon removal and rectification it has been fine since, and the added ventilation has got to help to get some fresh air into the front area around and ahead of the glass 'beam diffusers'.

 

Here is my full story, it involves A.) stopping water getting in and B.) allowing the light unit to vent adequately to disperse any remaining condensation:

 

 

 

Two tricks finally saw mine sorted, with some advice from here and a bit of ingenuity of my own.

 

1. Remove the headlight, disassemble it, get it spotlessly cleaned, then thoroughly dry all internal surfaces, then remove the black rubber trim from the front and seal the whole front edge with a good silicone or RTV sealant, most importantly this must be thoroughly dry before refitting and exposing to rain or it will seep through. DON'T RUSH THIS PART, ANY WEAKNESS HERE WILL ALLOW MOISTURE IN WHICH WILL THEN PREVENT THE RTV FROM EVER PROPERLY SEALING.

 

2. Get some clear, thin, flexible plastic sheet, like the front of one of these document wallets:

 

http://www.staples.c...ew-folder-lilac

 

You need to cut a piece from the clear material about 8 inches square, take it to your headlight and offer it up over the light such that some of this material can be trapped under the first torx bolt that secures the front of the wing (remove just this bolt). Once slipped between the wing top and the headlight, manouveure it about so it covers the top of the headlight and is just up to the front face of where the light meets the wing, cut to shape and then re-insert the torx bolt (poke a hole for it to pass through the plasic sheet) and it will clamp it in place. What this is doing is directing any water that runs down the wing inner channel away from the top of the headlight, as for me this was the source of the water that was then finding its way down and into the light. I'll try to get a photo up of this later if it helps.

 

http://i807.photobuc...zps352854d4.jpg

 

I've pulled the plastic sheet forward so you can see the sort of profile you need to make, then tighten it down so that the front edge is just level with the front corner of the wing and is less visible. This should now prevent water runoff getting into the top of the headlight and penetrating the joins within.

Edited by MP3

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If you re going to drill the top, place some 3M micropore tape over the hole (most chemists should have it).

 

The tape is breathable and will allow moist air out, but will deflect most water away from the hole.

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Did any of these work as a long term fix? Mine are getting condensation in already (had them in doors all over winter to dry them out properly and let damp in within 2 days!!!)

Best way to fix this? (Pre ffacelift) cheers guys

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Still bone dry and working as planned,in fact the cover sheet placed above stops the majority of rain water ever getting near the seals and weeping in.

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