Headlamp condensation

[outsmartsmart]

R230 SL350 2011 - couple of hours trip home in heavy rain yesterday and noticed condensation in headlamp this morning.

I'm aware this can be construed as 'normal' and lamps 'breathe' etc. but thought this was quite high amount and nothing at all in the RH headlamp.

Anything I should be checking and would this be a warranty claim (recently purchased the car with a warranty, not yet tested response)

 

[Craiglxviii]

Normal, hard thing to fix, won’t be honoured as a warranty claim I’m afraid.
CAN BE FIXED however through various means.

1. Remove all lamp holders and covers. Sit a hairdryer pointing into the back of the lamp at the biggest hole, on high for half an hour or so. Aim is to gently heat the air in the lamp unit up to the point where it evaporates the water, and with enough forced air movement that it changes the atmosphere inside the lamp unit envelope.
2. Drill a couple of 25mm holes, very carefully, in the back of the lamp unit outer casing, turn the lamps on for an hour or so and hope that this will do the same as 1.
3. After either 1 or 2, remove the big back caps and carefully glue inside them some dessicant gel sachets, 4 or 5 of the 1” type per lamp if you can. These will then control vapour deposition inside the lamp once you’ve got it warm.

 

[outsmartsmart]

I 'get' all you say and also know people talk about drilling holes (I'm sure you don't mean 25mm???!!!) or not in £1200 lamp units but its the oddity of the LH lamp displaying this and the RH nothing. Am I just as likely to find it the other way round another day. I haven't had the car long so unsure if this will happen 'all the time'. Not sure I want to be stripping the car down TBH, I bought a 'modern' model to drive it not tinker with it (this is my 'sunny day' toy car - being out in torrential rain as per yesterday will be/is an extremely rare event.

Thanks for the advice and thinking's though - I have done similar in 'old bangers' in my much younger years when on apprentice level wages and headlamps filling up with rain

 

[Craiglxviii]

No I did mean 25mm, or an inch if you want to get all Imperial! point is, you need to allow the internal atmosphere to disperse as easily as possible.

As to why one lamp mists when the other doesn’t, so many reasons. Different manufacture days or locations can lead to wildly different local humidity, therefore affecting internal atmospheric water content. It only needs to be by a few percent or so to hit the dew point in the U.K. and especially now as we have moved from hot & dry to mild & damp conditions.
Also affected by the asymmetrical engine bay layout, one lamp may be more subject to engine heat than the other and thus retain water as vapour, not condensation...

 

[Craiglxviii]

My considered suggestion is the hairdryer followed by the silica gel dessicant packs. If you can source the dessicant blocks instead then even better.

 

[LostKiwi]

Another common cause of condensation is failing seals where the lens meets the body of the lamp.
This allows high levels of moisture to penetrate the interior of the light unit which the built in moisture control design is unable to cope with.

 

[sl500amgsport]

If it's a summer fine day car keep it garaged and take it out on fine sunny days and you will see the issue disappear!

If it becomes an all weather working car it will resolve on fine days and only be a wet/damp weather issue from time to time.

The car is now 9 years old so outside manufacturer main warranty (used car warranties aren't worth the paper they are written on) and it is an R230 so expect much bigger issues when the Active suspension fails, the sbc packs up or water leaks into the boot. If you want something modern and reliable 5 years and under best, I will be offloading my R231 by the time it reaches 10 years for that reason.

Mercedes SL500 R231

 

[BillyBoy]

Personally I think the amount of condensation you have there, especially as it is only in one lamp indicates an issue. Unlikely to be covered by the warranty unfortunately but you could try. Most likely as LostKiwi said is that you have a faulty / damaged / deteriorated seal between the lens and the body. If you can access, then a.smear of clear silicone sealant all around may help, but not guaranteed. Also have a thorough check for stone chips etc. You will however, as said above, need to dry the unit out even if you can stop the ingress of new water.

 

[joderest]

I had/have this issue with my W163, always left headlight for some reason. I remove the headlight (as its very easy on this model) and take off the rubber bulb covers, remove the bulbs and sit the unit on a radiator over night to clear the water ( have also used a hair dryer) When clear, re install using rubber grease on the bulb covers, lasts about a year then has to be done again. All i can think is that heat from the engine gets drawn into the lamp, and the cold air hitting the front causes the condensation.

 

[Craiglxviii]

I had/have this issue with my W163, always left headlight for some reason. I remove the headlight (as its very easy on this model) and take off the rubber bulb covers, remove the bulbs and sit the unit on a radiator over night to clear the water ( have also used a hair dryer) When clear, re install using rubber grease on the bulb covers, lasts about a year then has to be done again. All i can think is that heat from the engine gets drawn into the lamp, and the cold air hitting the front causes the condensation.

Its more likely to be less heat on that one than the right side unit.

The problem with water vapour is that as the dew point changes in the external air, by even a few percent, with temperature changes it can cause differential condensation where one side seems “terrible” and the other side just fine.

Its a major pain in the bum for headlamp designers, even more so as we move to LED lamps more and more.

 

[Timeandleisure]

Hi, seeking advice please...
Just looked at a R231 but a little put off by the torrential rain storm within both headlamps and fogged up windows...
Should I buy the story that’s damp valet person got inside the car and it’s been sitting for a few days... it checks out history wise...MB has advised that they will sort it out as it could be due to not enough heat from LEDs lately and the mini hairdryer should resolve this.
Am I being too cautious? What are the possible situations in which this can occur?
Thank you!

 

[LostKiwi]

Be careful if condensation inside the car as it can be indicative of a wet interior. Insist they put a dehumidifier in it for a day then go back in a few days time to check it.

 

[sl500amgsport]

I used to leave my R231 on our drive, never had a condensation issue inside the car, Kiwi may be right, be cautious.

Sent from my SM-G988B using Tapatalk

 

[Timeandleisure]

Be careful if condensation inside the car as it can be indicative of a wet interior. Insist they put a dehumidifier in it for a day then go back in a few days time to check it.

Thanks, I did point out how musty it was, my old one never smelled.. they are going to rectify a few things but are clear that if I have any doubts then I will not proceed.
What a dampener, no pun intended, after a nice test run...

 

[Timeandleisure]

I used to leave my R231 on our drive, never had a condensation issue inside the car, Kiwi may be right, be cautious.

Sent from my SM-G988B using Tapatalk

Thanks! I agree, I am not very happy about it at all....

 

[malcolm E53 AMG]

This is well worth a watch - I know it’s a BMW but the way the headlight is manufactured will be very similar

 

[Timeandleisure]

This is well worth a watch - I know it’s a BMW but the way the headlight is manufactured will be very similar

Crikey! Thank you!!! If only everyone was as dedicated as him, then we wouldn’t worry...

 

[Timeandleisure]

I tried using lastvin but my searches have always come up invalid.... I type in WDD2314732F057228....am I doing something wrong?

 

[Kyoto50]

I have just swapped my 2011 W221 s350 for an 2014 SL350 and had this problem, but only with the SL. Was not happy about Mercedes saying its normal. Luckily bought mine from a reputable dealer who after testing replaced and recoded the headlight unit. I now have a matching pair of new ones as the other was faulty.

Hoping problem solved. Still missing some of the tech of the S class, in particular the reversing camera so may decide to retro fit one. That, and I do miss the 3 pointed bonnet star to see the end of the bonnet. Any advise welcome on whether replacing is possible.

 

[mioba]

Condensation in a headlamp cannot be normal. 1) it will interfere with the beam pattern and throw light in a wrong place - goes against having engineered headlamps. 2) the moisture will lead to corrosion of the electrics in the lamp and possible delamination of reflective surfaces in the lamp.

Reversing cameras can be retrofitted depending on car - commandonline.

Guess you could get a upright star - but not sure how it sits with the angle of your bonnet - ask at a dealer for the star - they need a special tool for fitting and its its one turn - a spring loaded clip. If you turn it wrong its broke and need a new star.