Headlamp condensation, this time a Xenon not Matrix LED

[ChrisP]

Hi again everyone,

After all the wet weather and a couple of high pressure spray car-washes recently, I have developed quite a bit of condensation in my nearside headlamp of my 2015 C7 A6 Allroad. This subject has had a lot of cover over the years and I've looked at what my searches have thrown up.  After checking for cracks in the lens, and found none, I've tried covering the external lens with aluminium foil and switching on full-beam for 2-30 minutes, with only marginal benefit, and next I'm going to try a couple of applications of hair-dryer treatment on medium heat settings. Responses to previous posts suggest that this may help, but that residual water vapour predictably condenses as the unit cools, so the approach maybe more effective in the summertime, and will certainly require several attempts.

I gather from Gareth's response to an enquiry about condensation in a Q7's Matrix LED Headlight lens in the last year or two that these are sealed units and that not much else can be done. However, mine are 2015 Xenons. I wonder whether this might provide any additional opportunity for sorting the problem?  I note that removing the headlamp unit sounds one hell of a hassle on the C7, as is even changing the bulb.

I don't live in much hope.

Chris

[Stevey Y]

1 hour ago, ChrisP said:

Hi again everyone,

After all the wet weather and a couple of high pressure spray car-washes recently, I have developed quite a bit of condensation in my nearside headlamp of my 2015 C7 A6 Allroad. This subject has had a lot of cover over the years and I've looked at what my searches have thrown up.  After checking for cracks in the lens, and found none, I've tried covering the external lens with aluminium foil and switching on full-beam for 2-30 minutes, with only marginal benefit, and next I'm going to try a couple of applications of hair-dryer treatment on medium heat settings. Responses to previous posts suggest that this may help, but that residual water vapour predictably condenses as the unit cools, so the approach maybe more effective in the summertime, and will certainly require several attempts.

I gather from Gareth's response to an enquiry about condensation in a Q7's Matrix LED Headlight lens in the last year or two that these are sealed units and that not much else can be done. However, mine are 2015 Xenons. I wonder whether this might provide any additional opportunity for sorting the problem?  I note that removing the headlamp unit sounds one hell of a hassle on the C7, as is even changing the bulb.

I don't live in much hope.

Chris

Hi the bulbs are easy to change, the condensation occurs for the following reasons, the vent tube on the side of the unit has either blocked or fallen off, the bulb cover seal has lost its elasticity and failed, the cover is accessible by the inspection port in the wheel arch liner, take it off then with the cover removed on the unit use the hairdryer, clear all debris from the mating surface between the bulb housing and cover finally give the rubber seal a good coating of silicone grease.

Steve.

[ChrisP]

Brill, thanks so much. 

Chris

 

[SlacksMeridian]

On 2/25/2024 at 9:22 PM, ChrisP said:

Brill, thanks so much. 

Chris

 

Hi Mate
Did you get anywhere with this. I put my car in for some very costly repairs and asked them to change the bulbs as soon as they did the passenger side headlight stopped working and the whole unit has very obvious condensation inside.

I trust the garage, although I never noticed any water gathering before they said that there was quite a bit of water in the headlight at the bottom of the front of the unit.

I bought the car with an issue (Rear Light Cluster) and since buying it I've had a door lock fail, an alarm horn fail. I paid for one of those android auto upgrade units (They're !Removed!, Dont bother) a new set of bulbs and a reverse camera that doesnt work.

I've been waiting about a month and a bit to have these repairs done after waiting forever on parts and now when fitting the bulbs one of the headlights has stopped working. I've had enough to be honest. I think its gonna be headlight + ballasts but I really can't be arsed at this point.

[Stevey Y]

3 hours ago, SlacksMeridian said:

Hi Mate
Did you get anywhere with this. I put my car in for some very costly repairs and asked them to change the bulbs as soon as they did the passenger side headlight stopped working and the whole unit has very obvious condensation inside.

I trust the garage, although I never noticed any water gathering before they said that there was quite a bit of water in the headlight at the bottom of the front of the unit.

I bought the car with an issue (Rear Light Cluster) and since buying it I've had a door lock fail, an alarm horn fail. I paid for one of those android auto upgrade units (They're !Removed!, Dont bother) a new set of bulbs and a reverse camera that doesnt work.

I've been waiting about a month and a bit to have these repairs done after waiting forever on parts and now when fitting the bulbs one of the headlights has stopped working. I've had enough to be honest. I think its gonna be headlight + ballasts but I really can't be arsed at this point.

Hi the ballast and bulb are easy to change the headlight can be dried out once the  bulb is removed with a hot air gun, removal of the unit is not to much of a drama as you can take th bumper fixings off that side and just pull the bumper back enough to get at the lower fixing on the unit, I did this on my A6 as I had to fit a new head light because the DRL had failed.

[ChrisP]

All sorted!  I removed both circular ‘hatches’ at rear of xenon headlamps to access the back of both bulbs, to which I eventually applied enough anti-clockwise twist, bayonet-style. I then simultaneously ‘ventilated’ the interior of the headlamp, with the Audi’s own 12v tyre pump tube inserted through one aperture, and using the other as exhaust, whilst applying a hair dryer to the exterior of the front lens. I kept the hair dryer moving, and continuously checked the lens temperature with my spare hand.
 

Two 20’ sessions on consecutive days were required to clear some pretty heavy condensation.

Hurrah!

Edited March 5 by ChrisP

[Stevey Y]

37 minutes ago, ChrisP said:

All sorted!  I removed both circular ‘hatches’ at rear of xenon headlamps to access the back of both bulbs, to which I eventually applied enough anti-clockwise twist, bayonet-style. I then simultaneously ‘ventilated’ the interior of the headlamp, with the Audi’s own 12v tyre pump tube inserted through one aperture, and using the other as exhaust, whilst applying a hair dryer to the exterior of the front lens. I kept the hair dryer moving, and continuously checked the lens temperature with my spare hand.
 

Two 20’ sessions on consecutive days were required to clear some pretty heavy condensation.

Hurrah!

Hi glad you got some resolution, well thought out plan, the lease should take up to 80c.

Steve.