misting up windscreen-water in boot

[azazel]

I have water in the rear of my 406hdi estate

My car was having windscreen misting up problems to such a point that I was having to open the windows to see, and have the windscreen demister on full blast. My aircon stopped working long ago. I thought the flap was stuck for resirculating air but that was fine. Replaced pollen filter (where flap is clearly visable with filter removed) also but the problem remained. Next I checked the outgoing vents at the rear and thats when I discovered large amounts of water in the boot area.

Im pretty sure that it comes in through the seals of the vents behind the panels either side where you gain access to the rear light clusters. The water gets in through spray from the rear wheels and then fills up and runs through part of the chassis at the rear of the car contaminating both sides. The high humidity causes condensation problems which forms between the roof and the lining and then water runs down around the light cluster wiring on the other side. This was misleading me into thinking that the roof bars were leaking or the light cluster but on inspection they appear to be sealed.

The rear of my car got damaged on one side which may have damaged the area arround the vent seal. The metal there is very thin and easy to straighten or bend. I removed the vents and cleaned them, siliconed the seal in and then siliconed the fitting into the car. This seems to have done the trick.

I hope this helps others as the symptoms can be quite misleading of the cause!

[azazel]

The problem remains so I removed the roof bars, resprayed them satin black and refitted them, siliconing between the gaskets and cleaning up the silicone that oozed out with white spirit. I hope this has fixed the problem but it will take time to find out. If not, im going to look at the aerial next and then the very rear windows. The roof bars dont look particularly well sealed from the factory so I suspect this is the problem.

Also, I dont think the windscreen demister is good enough if the aircon doesnt work. It simply doesnt move enough air.

[dirtydirtydiesel]

azazel,
Did you have to drop the roof liner to remove the roof bars ? , I would like to take mine of this year & get them powder coated
Many thanks, any pic's DDD.

[azazel]

You have to take the internal grab handles off and the trims and then fold the lining back enough to get a screw driver in. This has left creases in the lining which is glued in. Im not to fussed about that. I sprayed mine with satin black paint from Halfords. Looks nice. Big improvement as the original paint faded quite badly.

I would recomend first siliconing arround the bolt hole on the roof, then between the gasket and roofbar so that the two layers where water may get in are sealed properly. Excess silicone can be cleaned up after tightening with white spirit on a rag.

[azazel]

I still havent fixed the water leaking into the car. It drips down by the rear light cluster on the inner bit of the metal bodywork. Its not the light leaking. I dont think its the roof bars as Ive removed and siliconed them on refitting. Its not the vents down by the CD changer. I dont think its just condensation as it only happens when it rains. Im a bit baffled by it tbh!. Ive made a little cup out of the bottom of a 2 litre coke bottle that fits in the apperture of the rear light cluster and the water drips in there, so at least I know how much is getting in.