W204 C220 cdi Water Ingress

[James.whittaker]

Hi all I was wondering if someone can help me with a water ingress issue my car is suffering with. I seem to keep getting water ingress on the carpet just behind the front passenger seat in the footwell which keeps getting soaking wet after rain. It only seems to affect that area but I am not sure where it is coming from. My initial thought was that it is a blocked drain but my car does not have a sunroof so I'm not sure how I would go about checking the drains and where the location is or if it is another issue. Any help much appreciated

 

[Stardelta]

Have you had any work done on that door, like a electric window lifter replaced as the membrane behind the door panel can allow water in if it has not been resealed properly

 

[Jonesy161]

Also check that the door seals touch all round, you can do this by putting strips of paper round the frame about every 30cm shut the door and try to pull the strips out, any that pull out without resistance show a poor seal. The other way is to get in the car and have someone with a hose spray the area around the door, use a torch to check for water ingress.
Obviously, this is simply a check on the door aperture which worked for me when I had a similar ar problem.

 

[pembssurf]

100% sure it's rain water? May sound strange but dab a bit on your tongue. If it's at all sweet then it's the heater matrix... Helps exclude something mechanical other than that check door drain holes

 

[Dizzy]

The first place I would check (if only to eliminate) would be the drain vents at the bottom of the windscreen. These can become blocked with leaves and debris and lead to water entering the heater/pollen filter vents which are in that location. I know it's a long shot but water via the heater could run under the carpets and find it's way to the lowest point, the rear footwell.

 

[James.whittaker]

Thanks guys, I have checked the door seals and they are fine and also checked to make sure it is rain water. I am pretty sure it is blocked drains as it only started to happen since storm desmond on 5th December so I am guessing a lot of debris got into the drains. Are their any diagrams showing the location of the drains both the winshield ones and the door ones and also if they are blocked what is the best method to clean them out?

 

[Dizzy]

Hi, the two drains are below the windscreen (in the black area) and are located in the extreme corner on each side and you will access them easier with the bonnet open. (The central vents near the wipers are for heating and ventilation). The drain vents are quite small and narrow and can very easily become blocked and you can clear them with an old toothbrush, finger or similar. Try pouring a small amount of water down them and the water should drain under the wing onto the ground (I believe the outlet pipes run behind the wheel arch shields) if they are clear. If they are blocked further down then try a garage airline to blow them through. As far as I know (apart from a sun roof) these are the only body drains. The doors are quite simple, just look underneath each door and you will find two or three drain slits. These are easily cleaned with a lollystick or something similar inserted into them to clear any dirt.