[sepling]

First post here, but searched the forum and found nothing e90 specific where the seat cushion was wet without any other we areas so decided to post.

2006 325i-- Today I noticed the middle seatbelt in the rear seat was wet. I stuck my hand down the crevice between the upper and lower cushion and it was soaking wet! Took the rear bench cushion off and the sound deadening carpet pad material was soaked. I took the cushion inside to dry out and used towels to sop up as much as I could from the pad.

I have no idea where this water could have come from. I tested both rear sunroof drains and they both seemed to drain fine. There is a little bit of moisture beneath the passenger side rear floor mat, but not soaked like the bench seat.

There's no water damage or marks on the headliner or c-pillar trim.

Are there any other places I should be looking?

Thanks in advance for the help!

[jwalker87]

Did you recently drive in a lot of heavy rain or other wet roads? The only other thing I can think of is that the 'access door' to get to the top of the fuel tank is below the rear seat cushion. While I haven't explored there on my e90, I think the door accesses the top of the fuel tank, which is technically just the underside of the car. So if that panel/seal failed, then maybe it's possible for water to get up through it? Just an idea.

Check out the ~1 minute mark of this video:

[nsjames]

I'd echo that sentiment, there's not much else in that area to allow water in.

but man, I can't imagine that amount of water making it up over the tank and then up passed that access panel.

pop it and seal it though.

[bluewater328]

Maybe a gallon of water fell over in the trunk and it got below his fold-down seats?

[jwalker87]

Originally Posted by bluewater328

Maybe a gallon of water fell over in the trunk and it got below his fold-down seats?

Or maybe the trunk seal? That could have the same effect.

[nsjames]

trunk seal stuff is all behind the seat pan. You'd have water in the trunk.

[sepling]

Thanks for the replies folks. I’ll check and update

[Nando_e90]

What you need is 3M WindoWeld inside the door panel. Need to replace the adhesive. Happened to my a couple of months ago. Whenever it rained, I used to smell a wet odor coming from the rear carpet door and carpet was in fact wet. After many searches, found out that that adhesive was the problem. Replaced it with WindoWeld in all four doors and problem solved.

[Thorin]

I had the same thing with two of my Euro cars (the Saab and the Beemer). replacing the butyl rope was what did it. Work slowly, preferably on a warm day (when the butyl rope is more malleable), and do not tear the foam door skin. If the skin is torn already (i.e. by a ham-fisted tech replacing a window regulator), then you're going to need a new foam skin which costs ~$50. The factory butyl sealant breaks down anyways, as I found that three of my doors had some sort of butyl separation, and the fourth was separated and torn by whoever replaced the lock actuator.

Edit: for the above it wasn't the seat but the footwells that were getting wet. Now I re-read the original problem statement it's a little more confusing as to where the water could get in.

[Petercan1020]

Let me tell you I have an e92 and I did both vapor barriers because it's a two-door but the driver side rear seat underneath it was wet and it wasn't my access panel either so I'm trying to figure out what it was did you ever figure it out because it definitely not the vapor battery is leaking on top I don't even have vapor barrier I only have two doors so order would go to the foot Wells mine is wet underneath the rear seats not a lot of water but it's damp and like I said I checked the access doors and I don't see any present both my moon roof dreams are fine water flows them down them without clogging cuz anybody else have an idea I can't see anything coming in from my rear window or my side window please help