Condensation in Headlight

[Brian R]

Given you now have nothing to lose, how about creating a vent hole? I used to get this problem in my Jag and I could play heat onto the headlight and the condensation would disappear only to return when the weather cooled. I believe the condensation remains forever in the headlamp and simply cannot escape and will eventually return. A vent should allow the air inside the headlamp to be at ambient temperature and therefore shouldn't condensate. Surely worth a try?

Remember, warm air holds significantly more moisture than cold and will condensate when it comes into contact with cooler surrounds.

Edited March 20, 2022 by Brian R
Additional info

[agent_dess]

2 hours ago, matt8 said:

They all seem to suffer the same fate in varying degrees. I'm not sure what level of success you'll have with a replacement from a used vehicle at the scrap yard.

Where else can moisture be getting in?

It's much better, it's more of haze.. other option I have is to remove headlight, take all bulb and electrical parts off then fill with water to see where the leak is.

[agent_dess]

I find this interesting

[agent_dess]

3 hours ago, Brian R said:

Given you now have nothing to lose, how about creating a vent hole? I used to get this problem in my Jag and I could play heat onto the headlight and the condensation would disappear only to return when the weather cooled. I believe the condensation remains forever in the headlamp and simply cannot escape and will eventually return. A vent should allow the air inside the headlamp to be at ambient temperature and therefore shouldn't condensate. Surely worth a try?

Remember, warm air holds significantly more moisture than cold and will condensate when it comes into contact with cooler surrounds.

It's worth a shot, whereabouts do you suggest I create the vent hole?

That I said there are 2 rubber caps on the back of the housing, I took one off to find a sponge inside it, the cap half fits the cover so it appears that to a venting function.  I'm all for suggestions.

[Brian R]

9 hours ago, agent_dess said:

It's worth a shot, whereabouts do you suggest I create the vent hole?

That I said there are 2 rubber caps on the back of the housing, I took one off to find a sponge inside it, the cap half fits the cover so it appears that to a venting function.  I'm all for suggestions.

You may have answered your own question, i.e. remove one of the rubber caps along with any sponge but make sure it doesn't provide an inlet to splashed water. Personally I would have thought the vent should be at a low point given in due course water(condensate) would tend to pool. Obviously there may well be practical limitations as to how low down the vent can be created and of course again be wary of splashed water ingress. However, it seems to me if the respective air temperatures are the same inside/outside the headlamp, then condensate is less likely.

Seems to me the simplest test would be to try removing the rubber cap(s) and see if that yields a result.

[agent_dess]

9 minutes ago, Brian R said:

You may have answered your own question, i.e. remove one of the rubber caps along with any sponge but make sure it doesn't provide an inlet to splashed water. Personally I would have thought the vent should be at a low point given in due course water(condensate) would tend to pool. Obviously there may well be practical limitations as to how low down the vent can be created and of course again be wary of splashed water ingress. However, it seems to me if the respective air temperatures are the same inside/outside the headlamp, then condensate is less likely.

Seems to me the simplest test would be to try removing the rubber cap(s) and see if that yields a result.

Yeah I saw some video and came across a Mazda headlight which had the exact same rubber cover except the IS has 2 of them.  I might be able take the airbox out and access the rubber cover that way.

[agent_dess]

Looks like condensation is going away!

Originally before sealing it was 70% condensation

After sealing when I thought it was sealed about 25% returned.  Car has been parked in the garage for the last 2 days when it's been dark and cold, today looked at it and condensation is 5%.

I think unit is sealed now but I think what happened is because there was so much water inside and when I dried it i didn't cool it after with cold air to normalise the temperature so the warm air still had mositure which has slow been dissipating. Even of it remains at 5% I can live with it... Let's see how the next few days to.

[agent_dess]

And condensation seems to have gone 😁will need to see next time I wash car but I think issue is resolved.

[agent_dess]

So my battle with this is still ongoing... Now im hoping someone can explain the science behind what is happening.

When i was car, no condensation.

After long drive i start to get a bit of condensation happening around the highlighted area

But if i leave the car inside the garage for a few days it goes away.

Now the weird part when there is no condensation and its a hot day outside sometime i leave the car in the driveway in the blazing sun but towards the evening when it starts to cool down condensation begins to form in the highlighted area above.

Again if i leave the car in the garage for a day or 2 it disappears....

Can someone explain to me what is going on and what is causing the condensation to form??? 🤔

[agent_dess]

So googled the science part lol

I'm beginning to wonder if the o-ring around the indicator bulb isn't quite sealing properly when closed as this can only be accessed from the wheel arch and condensation is always toward the corner closest to indicator bulb.

 

 

 

[royoftherovers]

2 hours ago, agent_dess said:

So googled the science part lol

I'm beginning to wonder if the o-ring around the indicator bulb isn't quite sealing properly when closed as this can only be accessed from the wheel arch and condensation is always toward the corner closest to indicator bulb.

 

 

 

Back to the Dealer if the car is under any kind of warranty ?

[agent_dess]

6 hours ago, royoftherovers said:

Back to the Dealer if the car is under any kind of warranty ?

Sadly not

[agent_dess]

I think I have found the source of the condensation

This reflector is cracked/split compared to passenger side one. In my view this explains why condensation always shows on top front corner everything before spreading. 

Time for a new headlight, but there hard to come by at the scrappy!

[cadman2k]

It looks like they are on sale at lexuspartdirect @ £454

https://lexuspartsdirect.co.uk/product/lexus-is-phase-3-o-s-headlight/

Seems like some on eBay trying to get £600 secondhand...makes the new one a good buy if it's a complete replacement

 

 

 

[agent_dess]

40 minutes ago, cadman2k said:

It looks like they are on sale at lexuspartdirect @ £454

 

https://lexuspartsdirect.co.uk/product/lexus-is-phase-3-o-s-headlight/

Seems like some on eBay trying to get £600 secondhand...makes the new one a good buy if it's a complete replacement

 

 

 

Oh wow they have dropped in price, last  time I looked in LPD they were close to £600, I've seen a few used one on eBay for £250ish.  But for another £200 you get 1 year warranty. Thanks for pointing out on LPD @cadman2k 👍😁

[Malc]

On 6/25/2022 at 7:30 PM, agent_dess said:

Time for a new headlight

or the appropriate use of a clear sealant ............ 

Malc

[agent_dess]

1 hour ago, Malc said:

or the appropriate use of a clear sealant ............ 

Malc

Ive already been round the whole headlight with a sealant... So without taking the whole thing apart now which is not worth the time and effort, easier just to get a replacement or new headlight.

The exterior housing is fine.

[Malc]

and there's no slight cracking in any part of the lens itself presumably ?

Malc

[Bluemarlin]

As a last resort you might want to try Captain Tolley's Creeping Crack Cure. It's a liquid designed to find it's way into the tiniest of cracks and gaps, and seal them. Mostly used for sealing windows on boats, I've used it on windscreens and other hidden leaks before, with some success. Worth a go before splashing out on a new light assembly.

[agent_dess]

39 minutes ago, Malc said:

and there's no slight cracking in any part of the lens itself presumably ?

Malc

Nope.... i dont get any condensation when wash the car and i go in real closes with pressure washer.
As i mentioned in the post with the last picture the the reflector for the indicator bulb appears to be cracked at the top and this looks clearly different from the passenger side.

I get condensation when ive been on long drive or if the car has been standing in the sunlight/heat then towards the evening when it starts to cool down.

[Malc]

..... the gods aren't with you on this one then 😈

Malc

[agent_dess]

Ordered new headlight from LPD.

Some interesting design changes to body.



Its hard to see but the bottom half is now transparent, whereas on the original headlight it was solid black plastic

Everything else should be the same, once i get the old one out i will do another comparison.