Wet interior C pillar

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jsisas
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Wet interior C pillar

Post by jsisas »

Hi,

I have searhed for a while and read lots about wet interiors and soaking, carpets. However I could not find anything about wet C pillar.
Whenever it rains, my C pillars are wet from the inside. The water runs underneath the rear headrest pocket, where the speakers are on some version of the E24's. The rear carpets are completely dry, so I don't know where the water goes on from there. I have dissasembed the rear seat and experimented with water.

What I concluded was that the water comes in from UNDERNEATH the seal, gets in from the body side of the seal in the upper rear side window. When I pulled the seal for inspection it seemed fine, it was not cracked and it was not hard. The part where water leaks in are quite rusted. It's quite a small part that's rusted, about the size of a thumb, and goes along the side of the body underneath the seal. It's the same for both sides, both sides leak, and both sides have a bit of rust where the leak is coming in from. I need to swap out my rear side panel, but I think there is no point in doing that before I can stop the leak. Otherwise, the new side panels will start to rust out pretty soon too.
The sunroof drains seem in order because when I poured water into the sunroof it flowed out of the drainage and no leak was seen in the interior.

I have two suspects, I am not sure how big of a role the outer side plastic/chrome water deflector actually has in deflecting the water.
The seal from the store new is around 300usd, exterior plastic/chrome water deflector kit for both sides I think is around 500usd.

I don't know which one to try first to get the water to stop - either buy new water deflectors or go for the seal.
Or maybe I am missing something and it's something else that can fix it.

The white line in the picture shows where the water is coming in from and where it flows.
IMG_20220709_173445.png
IMG_20220709_173445.png (3.53 MiB) Viewed 227 times
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86_6series
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Re: Wet interior C pillar

Post by 86_6series »

The pictures show a clogged drain tube.
When you poured water down the rear drain tubes, water
exited from the cutouts behind the quarter windows?
jsisas
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Location: Manchester

Re: Wet interior C pillar

Post by jsisas »

Thats right, when i poured water into the sunroof the water ran out of the holes, that Are on the c pillars.

I saw that it leaked in when I poured water on the roof between the plastic water deflector and the body.
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Re: Wet interior C pillar

Post by 86_6series »

jsisas,

Do you think applying a clear sealer to that area would stop the water from entering?
jsisas
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Re: Wet interior C pillar

Post by jsisas »

I cant deny that I have thought about that, but I hoped there would be a prettier solution than this.

So I would have to seal off the whole plastic water deflector on the roof?
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Re: Wet interior C pillar

Post by 86_6series »

I reread your post and I'll retract my suggestion. You'll need
to repair the rust holes where the water enters. A body shop
should be able to patch that section without having to replace #1

https://www.realoem.com/bmw/enUS/showpa ... Id=41_0338

A photo of the rusted holes may show a different solution.
jsisas
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Re: Wet interior C pillar

Post by jsisas »

I finally found the pictures that I took when I disassembled the C pillar.


C Pillar pictures
IMG_20220710_124525.jpg
IMG_20220710_124525.jpg (402.62 KiB) Viewed 115 times
IMG_20220710_124520.jpg
IMG_20220710_124520.jpg (438.71 KiB) Viewed 115 times

Inside the rear window regulator
IMG_20220710_123606.jpg
IMG_20220710_123606.jpg (546.99 KiB) Viewed 115 times

inside the wheel well looking in from the rear window regulator
IMG_20220710_123614.jpg
IMG_20220710_123614.jpg (763.72 KiB) Viewed 115 times
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Re: Wet interior C pillar

Post by 86_6series »

"small part that's rusted, about the size of a thumb, and goes along the side of the body underneath the seal"

Can you photo this rusted spot?

I think the leak is coming from the upper corners of the rear window gasket.
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Re: Wet interior C pillar

Post by TimU »

jsisas wrote: Mon Sep 26, 2022 9:33 pm I finally found the pictures that I took when I disassembled the C pillar.
Jsisas, does that pipe go all the way to the lower skirting like the A Pillar pipe, or does it exit somewhere earlier?
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jsisas
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Re: Wet interior C pillar

Post by jsisas »

@86_6series
I think I had a memory fart, since when I found the pictures I couldnt find the rust spot either.
I have to take it a part to inspect it again. The car will go to garage this week, maybe next week I can take it a part again. Then I can take better pictures and investigate.
Meanwhile I can youtube on how to take off the rear window to inspect if I have any rust there.

@TimU
The pipe goes into the C pillar, where the water exits.
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Re: Wet interior C pillar

Post by 86_6series »

You should be able to peel back the window gasket edge to
locate rust damage.
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