Water In Trunk, Need Help

[1SGDHORN]

I went to open my trunk the other day on my 1987 M6 and water poured out from under the trunk lid trim. It rained pretty heavy and my thoughts are that water collected between the trunk and the spoiler and seeped into the trunk around the bolts and through the bold holes. The car has had the spoiler off when the entire car was repainted. I have done some research and read that the factory spoilers were cemented on. I wonder if when the body shop reinstalled the spoiler that they just bolted it on and didn't cement/seal it?

I know the only true way to find out is to unbolt the spoiler and have a look but, I'm just looking for advice. It's the only rational thing I can think of on where water would get into the car.

[RSheiman]

I bought 3M strip caulk for similar reasons. Waterproof, easily removed if and when. Same stuff as that big gob behind your BMW emblems.

[1SGDHORN]

I assumed some sort of caulking/silicone may not have been used on reassembly. I was not the owner of the car when it was re-painted so I guess I'll have to take the spoiler off to have a look. The emblem as well I guess.

[Dash01]

On E28, sometimes the trunk seal comes unglued from the sheet metal lip near the leading edge of the trunk bay. Water may be drawn into the gap between rubber and **** by capillary action, then it condenses on the metal inner surfaces of the trunk, and runs down and pools in the spare tire well, or whatever.

Perhaps the simplest, cheapest, most effective, and reversible cure is to install electrician's vinyl tape to cover the gap between rubber seal and sheet metal. PlastiDip also makes a skin to make it impervious, and may also work to close any gap between old rubber rear window seals and the window glass. With care, this can be done so it is not noticeable. On E24, sometimes body rust develops below the lower corners of the rear window glass, due to a similar untreated gap opening between rubber gasket and glass.

DEP makes a type of window caulk for winter use, which fills gaps but can be pealed off later. Home Depot and Lowes sell the stuff. I don't know if it comes in clear or black, but it may be an option if carefully used so as to be not noticeable. Silicone bathtub caulk from a tube might also work, and has 50 year guarantee...

[DesktopDave]

I've noticed the similar symptom on mine. Water collects on the lower trunk seal. My spoiler has studs though - the outer fastening nuts of the spoiler are near the rim of the trunk lid, outside the seal, and they block the water from draining down the trunk seals. This lets a little water in; I'll be resealing them somehow.

[markiehd]

interesting, I noticed a similar situation this year. I had the car painted 10 years ago. I too thought that it is coming in thru the spoiler, and that the paint shop did not use an sealant when they reattached. Not sure how big a job it is to take off the spoiler and fix. I believe it is on my list to attempt before winter....

[1SGDHORN]

When the PO had the car painted I do know the rear window was taken out (saw Pictures) but unsure if the trunk seat was renewed. The trunk was dry until I opened it. The water had collected under the grey trunk trim and when I opened the trunk it came leaking out from under it. The car was sitting on an angle with the rear lower than the front and it had rained pretty hard so, I assume water could/must have collected between the trunk and the spoiler (M6) and weeped in through the bolts or trunk emblem, collecting under the trunk trim until I opened it. The car was not driven at all in the rain so, things like the trunk seal, sunroof seal, rear light seals etc... would not cause the water to collect under the trim I would not think.

That's what I get for not putting her in the garage before the rain...

[DesktopDave]

I had something like that happen too (just lucky, I guess).

My old E23 had been repainted. The spoiler studs probably nicked the mounting holes when it was re-installed. The spoiler tends to trap water, and the mounting holes eventually rusted into huge openings, especially the roundel socket. They were entirely hidden. Water would seep through those holes, then sit in the inner pockets of the trunk lid. Every time I opened the trunk, water would flow down the inner lid, out through the liner, and into the trunk well. If I left it closed, the trunk stayed dry.

Here's a (bad) pic of the patched up holes. They're taped up but if you look closely you can see they hide a lot of damage:
http://i729.photobucket.com/albums/ww299/desktopdave/BMW/1984%20Alpineweiss%20745i/th_2014-03-28183609_zpse1562bf6.jpg (http://s729.photobucket.com/user/desktopdave/media/BMW/1984%20Alpineweiss%20745i/2014-03-28183609_zpse1562bf6.jpg.html)

[alpinacsi]

http://ace.imageg.net/graphics/product_images/pACE3-17458959enh-z7.jpg
This is what I have been using for nearly 30 years. I pull off a strip a few inches long and wrap it flat around the hole. Never had a problem with it leaking, drying out or not being able to remove. Was also used by Alpina when they installed the spoilers.