I have noticed recently when arriving at work after a 18 mile journey that the headlights are all misted up apart from the part directly in front of the bulbs.
Does this mean I have a gap in the seal of the headlight? Or could it be down to the cold weather and the headlight being warm?
Not had this on any other cars I have owned so can only assume it isn’t normal. I have done a search on the forum but could not find much on the subject.

Thanks in advance...

Chunk
 Range Rover Sport 2010 3.0 TDV6 HSE in Black
103,000 miles and a BAS Remap

I have added a photo to give you an idea. It was worse than this before and had improved slightly when I came around to take the photo. Range Rover Sport 2010 3.0 TDV6 HSE in Black
103,000 miles and a BAS Remap

mine was a bit like that in the snow which is extream conditions.

if the car is in everyday use, then it shouldn't be that bad.



On other cars I used to take the rear cap off for a week to let it dry out.

I had this on a previous vehicle, it's caused by moisture getting trapped in. I removed the headlight and drilled a 2mm hole on the bottom of the clear lens in a bit not noticed or likely affected by washing/rain. It cleared up overnight and stayed clear with no other issues.

Sounds crude, but very effective.

Dennis 13MY Range Rover Sport Autobiography SDV6 - mine
14MY Range Rover Evoque Dynamic SD4 Black Pack - wife's
99MY Defender 90 TD5, Soft Top Conversion - my toy, and bairns favourite

As per handbook -

HEADLAMPS - CONDENSATION
Misting of lamp lenses can occur under some
atmospheric conditions. This will not affect the
performance of the lamps and will clear during
normal operation.

 16MY Estoril Blue SVR.............
17MY Autobiography Dynamic - Corris Grey - WOW.
14MY Autobiography Dynamic - SDV6 - Fuji White
12MY Autobiography - SDV6 - Santorini Black - Dual View - Rear Entertainment - Sunroof.
12MY Autobiography - SDV6 - Orkney Grey - awesome ;(
2005 Java Black - 4.2 V8 Supercharged First Edition- will never be forgotten ;(

Most newer cars have a sealed headlamp which uses a semi-permiable membrane to allow for expansion and contraction of air in the headlamp cavity. On the L320 headlamps the membrane is a rectangular unit located just below the H7 highbeam auxiliary lamp opening. RH side headlamp unit shown below with the vent circled in red.



The membrane allows air to move in and out of the headlamp cavity but not moisture.

I actually removed this membrane to facilitate fitment of an H7 LED bulb kit (I did not know what it was for at the time). Being self adhesive I was able to stick it back in place but I don't know what damage I have caused to the membrane. If the membrane gets covered in a diesel oil film, which is quite likely in a high mileage diesel vehicle it may not work properly. This may cause the headlamp to draw cold damp air in via the bulb caps and cause condensation on the lens.

AVS-9 is the membrane size used on the L320 headlamps

The pre-facelift units had small rubber tubes to allow for venting the headlight unit. They still misted on occasion but it usually cleared with the light s on for a while. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

I’ve had this occasionally and was wondering if it was a contributory factor to my intermittent issue with levelling of the adaptive headlights. Haven’t got to the bottom of that on3 yet.

Highjacking the thread slightly I also get misting of the nearside rear light cluster. Is this common/normal? Robin
2008 Range Rover Sport TDV8
Gone:
Jaguar S-Type V8 4.2 Sport
MGZTT 190 2.5

Photo just taken in the dark after my car has been parked up for the last 6 hours. You can see the moisture at the bottom of the lens which is actually inside the light unit. It is the same on the other side. I have checked the self adhesive area on the back of the light unit and both were very clean although I did give them a wipe over.

I haven’t used the car for 3 days before today and it has been raining heavily all day. I am hoping I won’t have to replace both light units but will monitor it and see if the moisture level decreases. As said previously I have never had this problem on any other cars no matter what the weather has been like. Range Rover Sport 2010 3.0 TDV6 HSE in Black
103,000 miles and a BAS Remap

take a cap off each light, and leave for a few days.

Also drive the car with the caps off, as the engine heat will help dry out the lights, and move air about.


No need to buy new lights !

Okay will give it a go! The lights still work fine as the bit infront of the bulbs is clear. I think it is more of an OCD thing in my head that it annoys me as I know they shouldnt be foggy. Range Rover Sport 2010 3.0 TDV6 HSE in Black
103,000 miles and a BAS Remap

If moisture is already in the headlamp unit it is not going to go unless you physically remove the moisture.

I never remove the bulb caps unless I am in an airconditioned room with low humidity otherwise moisture can be introduced into the headlamp.

For the later L320's I suggest to remove the misting problem that the headlamps are removed into a low humidy environment and the air displaced from within the headlamp cavity and then place fresh desicant bags just inside and place the bulb caps back on and leave for at least 24h - remove the desicant before refitting the headlamps. If water is present within the headlamp cavity you should displace the air for some time until the water has gone before sealing them up with desicant.

If the problem reappears then water vapour/water is still entering the lamp some how and an integrity problem with the lamp housing should be suspected.

Have seen this a few times with my headlights but never bothered me as it always clears within a few minutes of having the lights on. My rear tail lights do it every time it rains or I wash the car but never seen any water in them, they just fog up a little so never worried about it plus I read somewhere that it's normal and they will clear under normal use which they always have. 2017 SVR. SVO Scafell grey Ebony interior
2012 3.0 SDV6 Autobiography santorini black with ebony/cirrus interior. Gone

Meiang wrote:

For the later L320's I suggest to remove the misting problem that the headlamps are removed into a low humidy environment

I didn't notice this in the owners manual, that bulbs should only be changed in a humidity controlled room.


There is so much water in them, need to get it out