Model Year 23/24 Looking for help – Headlight moisture issue (Formentor)

[Seatbeginner]

Hey everyone, new here — looking for a bit of help.


I’ve got a Cupra Formentor and recently noticed that my right front headlight is fogging up badly — not just condensation, but actual water droplets forming inside. It looks like dozens of tiny drops.


Before I take it in or try sealing it, I’d like to try drying it out myself.


On my previous car (a Škoda Octavia), there was a small plastic cover on the back of the headlight that I could remove. It let me blow warm air inside using a hairdryer, and that completely solved the problem.


I tried to find something similar on the Formentor — like a removable cap or breather valve — but no luck so far. I can't find any obvious access point that would allow me to get warm air inside the headlight.


Has anyone here dealt with this before? Is there a hidden breather plug or cap I’m missing?
Any tips would be much appreciated!

 

[trew]

If it's under warranty I'd get a new headlight.

If it's not under warranty I'd just put a hairdryer on it. I had this problem in a DRL on a previous car and using a hairdryer sorted it out really well.

 

[Seatbeginner]

Thanks for an reaction, but the question is where exactly should the hairdryer be used? I thougt that there is a small "hole" where should the air be blowing into. But I cannot see any

 

[DaveSmith]

I too had headlight condensation (see pictures). My car went into the dealers for this and the dreaded SOS fault.
The SOS fault was fixed under warranty. However, the headlights were not. The dealer told me that as the water was not "pooling" it is not covered under warranty. From what I can gather from this an other car forums (not just VAG), this is common issue for LED lights. Apparently, the Cupra headlights are not sealed and have a breather hole, but being LED they do not get warm enough to evaporate the any moisture that collects in the headlights. The dealer suggested that I go home and pressure wash the car in an attempt to make it look worse, then take some more pictures. Mine sorted themselves out once the warmer weather came along. I suspect that they will be the same in the coming winter.

 

[trew]

Thanks for an reaction, but the question is where exactly should the hairdryer be used? I thougt that there is a small "hole" where should the air be blowing into. But I cannot see any

I just heated the front 'glass'. Worked for me, may be different for you. If it were me, I'd try to apply heat as near to the relevant spot as possible - I know this is "stating the bleedin' obvious" ...just trying to help.

 

[Seatbeginner]

I just heated the front 'glass'. Worked for me, may be different for you. If it were me, I'd try to apply heat as near to the relevant spot as possible - I know this is "stating the bleedin' obvious" ...just trying to help.

Thank you for your time! I really appreciate it.

 

[Seatbeginner]

So, I’ve got a little update. I used a hairdryer to heat the front glass of the headlight. After about 45 minutes, almost all of the condensation was gone – the glass looked perfectly clear. I was really happy that I managed to get rid of it.


But the next morning (the car had been sitting in my garage all night), I came back to find the headlight looking like this


I honestly feel totally lost.

 

[Seatbeginner]

I tried it once more. I really completely dried it – there wasn’t even the slightest sign of humidity or water visible.
I used a hairdryer for more than two hours and did it very thoroughly. I even managed to find and open the ventilation tube (in the left corner of the headlight), so the moisture could escape.


The headlight was absolutely clear.


But this morning, everything is back again…


So the only thing that comes to my mind is: there must be a problem inside the ventilation tube – otherwise I honestly have no idea.


I'm just trying to understand the logic behind this.

 

[trew]

I tried it once more. I really completely dried it – there wasn’t even the slightest sign of humidity or water visible.
I used a hairdryer for more than two hours and did it very thoroughly. I even managed to find and open the ventilation tube (in the left corner of the headlight), so the moisture could escape.


The headlight was absolutely clear.


But this morning, everything is back again…


So the only thing that comes to my mind is: there must be a problem inside the ventilation tube – otherwise I honestly have no idea.


I'm just trying to understand the logic behind this.

That would frustrate and annoy the hell out of me - I reckon it's doing the same to you, understandably.

Is it possible to take a pic of the ventilation tube, so I can see what you're dealing with?
Also, the moisture must have entered from somewhere in the first place - my mind wanders to the possibility of an imperfection in the glueing/sealing of the components of the light unit, allowing water in - it could be the smallest, most imperceptible crack or gap? Personally, at this point I'd have the whole unit out, inspect and carefully apply small amounts of clear mastic wherever looks suspicious.
As for the vent tube - I'd make sure it's open, not blocked. Also, could the water have entered through the vent tube? Not knowing where it is and what it looks like, this is pure guesswork.
Then, while the unit's disconnected from the vehicle, use the hairdryer again.

It's frustrating, but I'm sure it's a problem that can be solved.

Anyway, you think you've got problems? - I have a little old Toyota iQ as my 'local runabout'. Right inside one of the red rear light units is the almost-white carcass of an earwig. Now THAT is annoying!...

Any removal tips welcomed!

 

[SRGTD]

@Seatbeginner - do you use a pressure washer to wash your car? I’ve read of instances on other forums where owners have experienced condensation inside their car’s headlamps as a result of over-enthusiastic use of a pressure washer.

 

[Delanor]

Its a common fault with many LED headlights and some cars get it worse than others, I used to get condensation in my V2 Formentor and I used a hair dryer on the glass to dry it out, now my VZN with Matrix lamps doesn`t suffer at all, the problem seems to be exasperated by how much night driving in damp/wet conditions you do as LED`s will eventually generate a small amount of heat but not enough to warm the lamp and remove the condensation, its the same with ice and snow HID`s or Halogens because of the heat they generate once switched on melt any ice or snow but with cooler LED`s you have to remove it.

Look at double glazed windows if a seal goes and cold, moist air gets in then the warmth from the inner glass causes condensation, the dessicant that is present absorbs any condensation until it becomes saturated and then stops working - then condensation!