PDA

View Full Version : Sunroof drain - what was BMW thinking



Espen
11-27-2008, 02:45 PM
I recently started to rebuild my rusty 535.
It was heavy attacked by rust along the side members (is that the right english word?)
When we cut off the old piece we saw the drain hose from the sunroof lying there, letting all the water from sunroof inside the front member, but we couldnt find any drain holes in the side member?
Is this right? With my new pieces welded in, I dont want the same thing to happend with the water again. We also discovered that the floorcarpet was soaked wet inside, so I must have a leak inside the car also.

before/after
http://gmx.no/wp-content/uploads/2008/11/kanalrust.jpg

http://gmx.no/wp-content/uploads/2008/11/dsc_0042.jpg

Just in case anyone is interested, i have some more pictures here:
http://gmx.no/2008/11/27/kanalene-straks-ferdige/

tim eh?
11-27-2008, 03:41 PM
I discovered a blocked sunroof drain shortly after buying the car, my carpet was also soaked. I'm not sure where they drain exactly, but for the front drains the water comes out the bottom just behind the front wheel. I fixed mine by blowing air through it - definitely a must to have these clear!

Espen
11-27-2008, 04:32 PM
Hmm so your actually came out somewhere?
Mine just ended inside the front side meber, just below the passenger door.
Its the same on the drivers side.

tim eh?
11-27-2008, 05:06 PM
Hmm so your actually came out somewhere?
Mine just ended inside the front side meber, just below the passenger door.
Its the same on the drivers side.

wow - your photos didn't work for me before...

looks like the same person tried to jack both our cars!

http://www.bimmernut.com/forum/attachment.php?attachmentid=5211&stc=1&d=1227823313

Yes - it's supposed to drain out the bottom... I'm sorry I never found out exactly where, it's in a bit more towards the centre.
Maybe you are missing some of the drainpipe.

Have you tried the rear sunroof holes?
Pour a little water in and see where it comes out, it should give you a better idea of where the front ones drain.

genphreak
11-27-2008, 05:13 PM
All my e34s drain at the rear effectively, through the sill, right in front of the wheel. If yours had no hole, it might have been 'fixed' by a zealous panel beater at some point...

BTW; are your drain hoses long enough? I have seen e30 drain hoses (the ones coming from the sunroof cassette) that seemed to shrink. e30s are only different in that they drain behind the rear wheel instead of in front.

Most important thing with these is to keep the drains clear up top, if leaves block up your drains in the sunroof cassette itself, then it fills until it overflows onto the headliner. This can drain covertly down the backs of the rear pillars covers, down the sides of the rear seats and under the rear seat cushion. From there, it floods the battery (if yours is under the rear seat) and the rear power distribution box, the latter of which is a bad thing. From there is floods into the rear carpets and potentially the front ones if it goes unnoticed (which is most likely).

Moral- check your drains every day if you park under trees. LOL!

Espen
11-27-2008, 05:18 PM
Ive read about the leaks down in the headliner, but i thought it would be easy to see the headliner soaked. It looks dry.. The battery is also dry. So I think the water must be coming from the front end.

Didnt look that much at the rear, but as far as i can recall, there was no drain there.

tim eh?
11-27-2008, 05:24 PM
There are 2 holes in the rear much like in the front.
Worth checking... you need half a cup of water.

It sounds like you are just missing some tubing in the front... all you really need to do is to get what you have to drain out the bottom somewhere.

Espen
11-27-2008, 05:28 PM
There are 2 holes in the rear much like in the front.
Worth checking... you need half a cup of water.

It sounds like you are just missing some tubing in the front... all you really need to do is to get what you have to drain out the bottom somewhere.

I will check this next time I visit the workshop.
So the drain tub hose/tube follows the A-pillar, is supposes to go down into the sidemember, and all the way back to the rear wheelarches? My hose was cut of about in the middle of the passenger door.

attack eagle
11-28-2008, 02:43 AM
they drain into the rockers

There is no exit other than that provided by the not completely sealed and not fully seam welded rockers, IE between the two pieces of metal.

shogun
11-28-2008, 03:13 AM
On the E32:
front A-pillars both side: goes under the doors into the door sills. There it drain thru the jack points. I remember that Patrick C750 on Bimmerbioard found out that his jackpoints were bended and closed the drains. He drilled a hole into the underside of the sill.

Rear: each side C-pillar. Goes into the C-pillar, and from there outside the C-pillar into each side wheel house, there the hoses end, You cannot see them usually, because the wheel house is cladded with this plastic mud/water guard insert or what that is called.

Espen
11-28-2008, 07:24 AM
Thanks Shogun.
My jack points where long gone, thats why we didnt see the drains.

attack eagle, what does "rockers" mean? - my english isnt all that great.

uscharalph
11-28-2008, 09:43 PM
I never checked mine. Something to add to the list before rainy season.

Jehu
11-28-2008, 09:50 PM
The drain plug on my right door sill was rotted when I bought it... i had it sealed like the OP at a body shop. When i read this my herart sank. I have to assume this was the cause of the rotted drain and I only made it worse by not cleaning this drain but sealing that completely now... Ugh..

genphreak
11-29-2008, 09:05 AM
Ive read about the leaks down in the headliner, but i thought it would be easy to see the headliner soaked. It looks dry.. The battery is also dry. So I think the water must be coming from the front end.

Didnt look that much at the rear, but as far as i can recall, there was no drain there.

There are 2 in the rear corners, just like the front- same on all BImmers. And no, if either leak it may be impossible for you to see at any point. You don't want to work this out thru misadventure or neglect- or one leaf getting into the wrong place...