Wet Back Seat/PDC/Other water leak?

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bmw123
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Wet Back Seat/PDC/Other water leak?

Post by bmw123 » Mon May 07, 2012 8:53 pm

Hi, First time post on the forum, having a few issues which following research on this site turned out to be the PDC sitting in water I thought I would start off by saying thanks!

But now I need a bit more help:

Identified that PDC sitting in lots of water and other side had water in it as well. Dried out both sides and siliconed all round the vents on both side. At the same time had noticed the back seat was wet which assumed was related and water was running up the car. Removed rear seats and carpet underneath finding lots of water, which again I dried out.

But now having had everything out for a couple of weeks to keep an eye on whether water is returning and allow everything to dry out throughly. But am still getting some water in the little areas to either side of the boot (ones the pdc sit in) but only a minimal amount and am getting water welling in the bottom of the rear seat area. Doesn't appear to come from rear light area (cutout to access light bulbs)

Have been unable to identify where the water is coming from that is appearing in the wells but final have a slight indication where the water might come from that appears in the bottom of the rear seat it is the threaded holes at the back of the seat area

Image

Image

Anybody know where this water might be coming from?

Thanks

robsaboy
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Re: Wet Back Seat/PDC/Other water leak?

Post by robsaboy » Mon May 07, 2012 9:04 pm

Mine took a while to dry out - water trapped in voids?

Put some cloths where the seats were and find a steep downward hill. set off and stop a few times help the water flow out. Also get in the boot with a torch and get someone to hose down the rear of the car to see if and where its coming in.
M140i, Mineral Grey

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Re: Wet Back Seat/PDC/Other water leak?

Post by bmwnoob » Sat Sep 01, 2012 10:33 pm

Hi,

I've been having this problem myself. Soaking wet rear seats and water in the boot (battery and and PDC).
I went to a garage and let them try to solve the leaking problem. They told me that they had found and fixed a leak in the rear, left door. They also kept the car for two days, just to make it dry out. Everything seemed fine.

Unfortunately, the seats got wet again when I drove home that same day. I then did some research on the www and found this forum. Read some posts about leaking air-filters in the boot etc. I then went to a second garage (with this information) to have a second look at the problem. They could not find any leaks. But they confirmed that the seats where soaking wet.

Until now it had seemed to me that the water was coming from the sides of the car, rear wheels or doors. I decided to have a look myself and found that the water was actually coming out from the bolts holding the seatbelts, filling the room underneath the seat-pillows, making them soak up the water. I crawled under the car to see if I could find where the bolts tightened on the other side of the chassi. I could not find them, as the car has a double bottom-plate. What I did find, was two plastic-plugs. I pulled one out and I guess 0.5L of water poured out of the hole. Pulled out the other plug, and water poured out here as well. To me it seems like there is a room under the seats that fills up with water, and when its filled up, the water leaks into the seats trough the seatbelt-bolts and to the boot.

The car is now drying up and everything looks fine. I hope to see that the water in this "hidden" room is not filling up again. Possibly it came from the rear-door leakage that is now already fixed. But only time will show..

Inside car. Leaking seatbelt-bolts:
Image

Underneath car. Location of holes where plastic plugs where fitted (removed on picture):
Image

The plastic plugs:
Image

BMW1989
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Re: Wet Back Seat/PDC/Other water leak?

Post by BMW1989 » Wed Oct 24, 2012 5:36 pm

Hi All,

I've recently purchased my 118i M Sport and have been encountering exactly the same problem. Spoke to BMW today and not willing to help at all without relinquishing me of £300 to 'diagnose' the problem of which they say they are unaware! - Sceptical.

I too have now stripped the car down (back seats out and boot area) and found a good 2cm of water pooled under rear seat bench, with the foam and felt sodden. Likewise, in the boot, the void on passenger side was also full of water.

I've ruled out the vent/filter in the boot and also rear light after water pressure testing and as with comments in the post, have noticed water coming out of the two eyelets. Again, I've had the car in the air and released the two drain plugs with a similar amount of water falling out.

Two things:

- could the water storing in the 'box chassis' area be anything to do with condensate from the air conditioning system? (Do you guys have air conditioning?)

- how is the water travelling from the box chassis (near seats), to the boot void? Anyone got an idea on any runs between the two?

Hopeful of replies.

Thanks,
James

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Re: Wet Back Seat/PDC/Other water leak?

Post by Slippers » Fri Oct 26, 2012 2:28 pm

I have also discovered my back seats were soaking this week. Don't normally have rear passengers which is how it was discovered, could have been like it for a while but i've not noticed any damp smells until this week.

I took apart the boot and found a little water by the vent on the passenger side, and loads of water in the PDC area (which must be why it stopped working about 6 months ago). I've got out as much as I can, the seats seem to be drying out but I can't be too sure. Going to need to take the rear seats to check under them and keep an eye on it I guess.
Simon

Previous: 118d 3 door in black - The Black Bean

Current: 118d 5 door M Sport mineral grey with many extras and M Performance brakes - Greyskull

Ryan85
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Re: Wet Back Seat/PDC/Other water leak?

Post by Ryan85 » Thu Jan 10, 2013 10:54 am

Slippers wrote:I have also discovered my back seats were soaking this week. Don't normally have rear passengers which is how it was discovered, could have been like it for a while but i've not noticed any damp smells until this week.

I took apart the boot and found a little water by the vent on the passenger side, and loads of water in the PDC area (which must be why it stopped working about 6 months ago). I've got out as much as I can, the seats seem to be drying out but I can't be too sure. Going to need to take the rear seats to check under them and keep an eye on it I guess.
Same problem for me!! Took apart the back end of my car and found this!!!

Image
Image

I just pushed the the plugs out to get rid of the water, but found that the vents had about 5mm gap at the bottom that wasnt sealed against the body panel!

Seats were soaked so i took them out and sat against a radiator, Still a big water mark on them tho,

But hopefully problem solved??

Ryan

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56 plate, 118d se, Quartz blue, private plate

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Re: Wet Back Seat/PDC/Other water leak?

Post by bmwnoob » Wed Mar 20, 2013 10:09 pm

bmwnoob wrote: The car is now drying up and everything looks fine. I hope to see that the water in this "hidden" room is not filling up again. Possibly it came from the rear-door leakage that is now already fixed. But only time will show..
Just a little follow-up to my previous post. The leakage (first believed to be from the rear-door sealants) was NOT fixed. Still, no mechanic has been able to locate the leakage. Anyway, there is no problem in running the car without the "plugs", meaning the water will just run trough the car. Without the plugs, it has not been any water in the seats or the boot. I don't like the Idea of water running trough the car, but at least it is not a problem any more.

My theory is that water is first leaking into the room underneath the rear seats. Then, when this room is filled, the water travels into the boot and seats when driving.

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Re: Wet Back Seat/PDC/Other water leak?

Post by jamesworld » Fri Sep 25, 2015 10:49 pm

Hi. I had this problem this year. Researched this site and removed the box section plugs as described, lot's of water.
It's coming in from the rear corner well's. When they fill up it flow's into the chassis box section and up over the rear axle and flows down to end up filling the box section where the seatbelt bolts go in. Once there it is trapped. Taking out the plug's drain's the box section.
Obviously this requires a lot of water in the rear corner well's. Also remove plugs in rear box section to drain these.
2005, 118i.

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Re: Wet Back Seat/PDC/Other water leak?

Post by BMW = useless » Fri Dec 16, 2016 1:21 am

Have just suffered a water logged back seat and only got to the bottom of it from the help of this forum so thankyou.
In regards ro BMW's response..they are aware of it and are sorry !!
For such a fault to be known and ignored by BMW is quite shocking and future customers should be told because I wasn't.

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Re: Wet Back Seat/PDC/Other water leak?

Post by Slippers » Sat Dec 17, 2016 7:16 pm

I saw someone on a FB group who has had issues with water on his F20. I would have thought this would have been sorted for the newer model
Simon

Previous: 118d 3 door in black - The Black Bean

Current: 118d 5 door M Sport mineral grey with many extras and M Performance brakes - Greyskull

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Re: Wet Back Seat/PDC/Other water leak?

Post by b-a-r-t » Sun Oct 01, 2017 3:47 pm

jamesworld wrote:
Fri Sep 25, 2015 10:49 pm
Hi. I had this problem this year. Researched this site and removed the box section plugs as described, lot's of water.
It's coming in from the rear corner well's. When they fill up it flow's into the chassis box section and up over the rear axle and flows down to end up filling the box section where the seatbelt bolts go in. Once there it is trapped. Taking out the plug's drain's the box section.
Obviously this requires a lot of water in the rear corner well's. Also remove plugs in rear box section to drain these.
2005, 118i.
Hi James, I have the same issue, and I believe you are right.

The water enters the car through the tail light rubbers where it collects in the rear corner wells of which one holds the pdc circuit board. Then the water leaks through tiny holes into the chassis box section collecting in the area behind the seat belt bolts.

I believe the water is mainly entering through back light rubbers when they are bad. This I tested and I ordered new rubbers. Air vents are behind a cover in the wheel area protecting it from a lot of water coming in, so I figured not a lot of water can flow there into the car.

When you repaired it did ever any water came out under the seats again ?

Kind regards,
Bart

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Re: Wet Back Seat/PDC/Other water leak?

Post by Thorttle01 » Sat Jun 30, 2018 8:58 pm

The Water is leaking around the air ventilation directly to PDC area. You haved probably an accident. One fresh driver hit my e87 from right rear side this week. There is only small scratch on the bumper from outside. Yesterday was rainy day and i drived the car around the city. After that is pdc failure comming and smoke from right rear side. I openned my trunk and check pdc unit, there was lot of Water . I disconnected pdc and dried the area. I never had problem with water leaking before. I sad there must be something wrong after the accident. Stal around the tail light was OK. Now i checked the chasis around the vent with my fingers - the was nothing visible with the eyes. But the chasis is pulled in from rear bumper - the metal plates are stable like bottle from coke. The water is simply flowing around the vent, because the chasis is pulled in and there is distance between the vent seal and car chasis.

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