[mayhs]

Over the last few days when driving off I've heard a water trickle/bubbling sound coming from the rear seat area. Investigated further and found the entire rear passenger side footwell is soaked. I've soaked up loads of the water but after raining it fills up.

I've searched the forums and know about the vapour barrier leaking issue and also found a bit regarding leaking A/C ducts and sunroof drains.

However I cant see any signs of where the water would be coming in from. The carpets around the footwell are dry, even under the front door and B pillar and considering how much water accumulates I'd expect to see some signs of dampness on the carpets around the footwell.

I'm going to pull the door card off this weekend but just wondering if anyone else has come across this?

I've got a pre lci 330d saloon with the sunroof option by the way

[bishbosh]

I'd guess that the sunroof drain is blocked. Either that or the vapour seal behind the door card.

[rasa bmw]

rubber around rear door is a common culprit also..

[mayhs]

Bit of a update. Came home and the floors soaked again but it seems the water is coming from the black plastic vent on the floor! Managed to wiggle it a little bit and could hear water sloshing around inside!

[mayhs]

Also noticed today that with the heating on I get hot air out of the front vents and rear centre console vents, but only get cold air coming out from the rear passenger heating duct from under the seat

[Unknown_Car]

Rubber around the door is bad. Take it out and re-silecon it I had to do this to my e39,s.

[mayhs]

Managed to get a bit of the trim off today. Turns out it was a blocked sunroof drain, water was running down the headliner and along the front door rubber seal and then pooling in the front and rear passenger seat floor. Pulled up a corner of the front carpet and managed to pump quite a bit of water out probably a few litres. The foam is still pretty damp/wet but might try to use a dehumidifier to dry out the cabin.

Ended up blowing some compressed air down the sunroof drain and it seems to have done the trick but need to remove the roof-lining and see where the sunroof drain actually runs.

Praying for a hot summer...

[mayhs]

So another update to my troubles!

After the summer heat all the foam has finally dried out in the passenger front footwell. But after a bit of rain today I decided to check to make sure that the leak (thought to be from the sunroof drain) had fixed the issue but it hasn't.

It seems that the water is leaking from the side of the glove box, the sponge bit is damp however I have no idea how water can be leaking though the side panel. I've checked the drains inside the engine bay and they are clear.

Any ideas?

[autokunst]

Wondering if you ever definitively resolved your issue. Two days ago I was driving in a hard rain, and I heard the exact same trickling/bubbling sound. Last night I noticed that my drivers (left) rear foot well is soaking wet. The front is dry, and the right side front and back are dry. I plan to check all of the posted suspect areas later today, but any advice is appreciated. Thanks!

[mayhs]

Unfortunately not, but it seems (for now) that the water ingress has stopped and I've not noticed any more damp.

I would double check the front (left), just try and squeeze the carpet and listen out for water.

[Tuna]

Originally Posted by mayhs

So another update to my troubles!

Any ideas?

Just curious if your has ever been in an accident or had body work done?

[mayhs]

No, not had any damage or body work done in that area or side of the car. Its been a while and I think it's stopped. Not had any damp over the last two winters so hopefully it was just the sunroof drain...

[autokunst]

I can report that I fixed my issue by cleaning the sunroof drains. One or more of them was clogged, but it was an easy fix and I've had no more issues since (2 years).

[mayhs]

Originally Posted by autokunst

I can report that I fixed my issue by cleaning the sunroof drains. One or more of them was clogged, but it was an easy fix and I've had no more issues since (2 years).

Just out of curiosity, how did you go about cleaning the drains?

[autokunst]

Originally Posted by mayhs

Just out of curiosity, how did you go about cleaning the drains?

I feel like I am forgetting some of the details. But I used nylon weed trimmer line and carefully pushed it through the drain lines. On the two front drains, I ran the line down from the top as far as I could get it. The drain holes are in the corners of the sunroof "gutter". I also pushed the trimmer line up from the front drain outlets behind the front wheel wells. For the rears, I pulled the side panels from the trunk to expose the drain lines. The lines have a 90 degree rubber elbow there. I pulled the plastic hose drain from the elbows and ran the trimmer line both directions (I think the left rear was where my clog was). After that, I tested by running some water from the gutter out all (4) corners, and they ran freely. The drain outlets "squint" down from a circle to a flat orifice when they exit, and I also pinched those open to make sure any debris could exit the lines while I rinsed them. Good as new!

[mayhs]

Thanks for the info, I'll definitely try that just to make sure the drains 'remain clear'. I tried to use some thin flexible wire that I had but tried putting it in from the sunroof drain end but didn't get very far at all. Managed to jig it about a bit and it seemed to work but can't say I was overly satisfied with the whole process.

[autokunst]

I am sorry that I don't seem to have photos of this operation (I did but they seem to be MIA). There were several different types of weed trimmer line - some very thin and flexible and other quite stiff. I used one that was neon yellow/green in color and three sided (line an extruded triangle). It was reasonably stiff so I could push it through the tubes pretty well. But I did use a match to melt the business end of it so it wasn't sharp. I didn't want it to poke right through a formed rubber corner within the downspout system.

Originally Posted by mayhs

Thanks for the info, I'll definitely try that just to make sure the drains 'remain clear'. I tried to use some thin flexible wire that I had but tried putting it in from the sunroof drain end but didn't get very far at all. Managed to jig it about a bit and it seemed to work but can't say I was overly satisfied with the whole process.

[sfarisminhas]

I have found this to be such a PITA. I spent the summer of 2020 taking out the seats, lifting the carpet and drying out on both sides of the car. I had noticed that it was mainly on the front passenger side. I have since replaced both vapour barriers and door clips. I also noticed that the plastic tray near the firewall under the windscreen was loose which I have sealed and fixed.

[Bakerc_1993]

I'm having similar issue, Rear passenger footwell is drenched with water. Checked front drains by windscreen and they were all clogged with leaves so have removed and cleaned out. However we had real bad rain fall last night and it would appear more water has managed to work its way in as the water dampness of the carpet is much worse now when I slap the carpet water goes everywhere.

Hope someone can assist, Does this sound like its likely to be the vapour seal as I see this is a common fault! is there a way of testing to see if it is the vapour seal?

[hfount]

Originally Posted by Bakerc_1993

I'm having similar issue, Rear passenger footwell is drenched with water. Checked front drains by windscreen and they were all clogged with leaves so have removed and cleaned out. However we had real bad rain fall last night and it would appear more water has managed to work its way in as the water dampness of the carpet is much worse now when I slap the carpet water goes everywhere.

Hope someone can assist, Does this sound like its likely to be the vapour seal as I see this is a common fault! is there a way of testing to see if it is the vapour seal?

Same here '08 328xi driving me nuts. Checked the 4 moonroof drains are clear. It rained last night and sure enough this morning I found a puddle in pass rear footwell. (FYI, the car is parked uphill on my driveway.) Felt around the front door and rear door for dampness, felt around the ceiling for wet spots, opened doors, and checked for wetness. Checked the front pass carpet and sides, but nothing. Then I sat inside the vehicle while my daughter poured water from a hose for 5 minutes straight onto the roof, front windshield, side windows, back window, and the moonroof. Nothing. It's driving me nuts!

[whyzee125]

Originally Posted by hfount

Same here '08 328xi driving me nuts. Checked the 4 moonroof drains are clear. It rained last night and sure enough this morning I found a puddle in pass rear footwell. (FYI, the car is parked uphill on my driveway.) Felt around the front door and rear door for dampness, felt around the ceiling for wet spots, opened doors, and checked for wetness. Checked the front pass carpet and sides, but nothing. Then I sat inside the vehicle while my daughter poured water from a hose for 5 minutes straight onto the roof, front windshield, side windows, back window, and the moonroof. Nothing. It's driving me nuts!

Try driving through a car wash a few times? That kind of pressure should make it easier to find.

[Victor2vt]

Check that your windscreen is a BMW OE, I’ve had the same problem and it was found to be the non OE windscreen did not fit 100% and was the cause of the leak