W205 C250d condensation

[design guru]

I have a C250d 2016 W205 and the windows get steamed up quite a lot. I know its cold this time of the year but this a not just condensation, I get a full build up of mist like they have been sprayed with a water sprayer. It happens mostly on the rear window but often its on the front windscreen and sometimes even the glass sunroof, and this is even when the interior lining is closed.

I have checked the seals and there are no obvious tears or loose fittings, the sunroof drain holes are clear and when the roof is opened there is no water or mist wound the fitting. Its definitely not from the roof and all the carpets are dry including the boot lining.

I use the air con and its working fine. I would expect a small amount of condensation especially when the windows are extra cold this time of the year but the build up of mist is too much.

Any help would be appreciated.

 

[W1ghty]

I have a C250d 2016 W205 and the windows get steamed up quite a lot. I know its cold this time of the year but this a not just condensation, I get a full build up of mist like they have been sprayed with a water sprayer. It happens mostly on the rear window but often its on the front windscreen and sometimes even the glass sunroof, and this is even when the interior lining is closed.

I have checked the seals and there are no obvious tears or loose fittings, the sunroof drain holes are clear and when the roof is opened there is no water or mist wound the fitting. Its definitely not from the roof and all the carpets are dry including the boot lining.

I use the air con and its working fine. I would expect a small amount of condensation especially when the windows are extra cold this time of the year but the build up of mist is too much.

Any help would be appreciated.

Check the drains under the front windscreen and flush them clean ?
Any water in the spare wheel well ?
Any leaks around the rear light fittings ?

 

[design guru]

Check the drains under the front windscreen and flush them clean ?
Any water in the spare wheel well ?
Any leaks around the rear light fittings ?

The rear is the worst, I have checked the drains in the front and they are clear, its the back window that mists up so bad you can run your finger through it and water will drip from your finger. Rear lights are fine. Since cleaning the rubber sills the front is not as bad but the rear still the same. I am guessing the boot sill, I want to remove the black plastic runners that go from the rear window to the bottom of the boot lid as there seems to be a build up of sludge but can't figure how they come out. Don't want to brake a clip and find I need to replace the whole strip.

 

[JHS]

Mine (S205) mists up quite quickly if I run without the AC on. I will have to check the front drains.

 

[Smiley]

If you have that much misting up then you definitely have quite a bad leak somewhere. It does not help much now but it is easier to find the problem in the summer with a hosepipe; even then it is not easy. The problem is that all that condensation is all over the electronic components in the car and it is only a matter of time before they start failing. It is worth persevering to find the cause.

 

[Drewski09]

Any water in the spare wheel?

 

[zipdip]

Sounds like it is not so much a car but a submarine,check that the doors are draining,it would seem you have checked most of the other places.

 

[design guru]

Mine

Any water in the spare wheel?

I did check all the places after seeing a few past incidents when I googled it, boot is dry all carpets are dry. The only bits that have dirt behind it is the plastic runners which go along either side of the boot from the back window, not sure how they remove and being plastic I don't want to force them off and cause damage