Is this a RARE E39 option?

[AngryPopTart]

The rear passenger floor miraculously becomes soaked with water! Oh, and it did rain. I can't figure out where it's coming from, unless it came in through the door pillar from the sunroof area or something odd like that. I reached down to find my squeegee and got a handful of WET, but the other floor areas are not wet at all, and I don't see anywhere it could have come in through the door rubbers. I'll go look again, right now. I should wet-vac that stuff out anyway. thx_info~ in advance!

[winfred]

i've gotten a couple e39s with the drains in the rocker plugged, one car you could hear the water sloshing it was so full and both cars dried up after we blew them clear, they are on the bottom of the car and you gotta look for the little almost bulge with a crack and that's the drain, run a piece of wire up in the hole to clear

[Zeuk in Oz]

I have had something similar happen to my 528iT when one of my sons was driving it and I think it happened (both front & rear drivers side carpets were soaked) because my son did not understand how the remote control key works.

If, when unlocking the car, you hold the unlock button down just a little too long, the windows start to wind down. In our case this seems to be what happened and the rain came in from one side.

I cannot be certain of this as I did not witness the windows down at all, but it is the only scenario that makes any sense as it has not happened again.

Alternatively, open & close the sunroof a few times to make sure there is nothing caught there.

[Omega]

Unfortunately this is a pretty standard e39 option. :( It's a very well documented problem. Just Google for "e39 wet floor".

Basically it's due to the mastic that sticks the water shield membrain to the door frame becoming brittle and allowing water past to flow past into the passenger compartment.

To see if this is happening to you, open the offending door and run a hose/watering can along the outside rubber seal at the door/window. If the membrain has failed you will see water escaping from the bottom of the door panel.

I had this problem with my e39 (used it as a really effective bargaining tool when I bought it and fixed the problem for £1....:D .)

To fix it, pull the door panel off and then remove the inner formed membrain from the door frame. Either go to BMW and order the mastic on a roll (about £25- +vat) or go to a DIY store and buy "gutter/drain mastic" which is a black goo in a tube (I got a tube for £1) Be warned though the gutter stuff takes about 3 days to dry and it stinks but when dry is odourless.

Remove all of the old mastic from the membrain, apply the new and stick the membraine back on. Simple and effective.