Solution to E30 convertible top locker filling with water

[Trevornz]

Hello Folks,

I have searched the forums before to try and find out why my E30 convertible top storage locker (the space that the top uses when the top is down) fills with water and whilst some information has been helpful, I could not find anyone who had actually worked it out and actually fixed it with a clear description. After nearly a year of trying different things, I have now worked out exactly what is going on and fixed the problem. This posting is so you can benefit from that learning.

Problem - after rain, the convertible top locker fills with water, after heavy rain it is so bad you can hear it sloshing about as you drive. When it gets warm, the water evaporates into the car, causing it to get humid and everything goes mouldy. The only solution up until now was to open the locker and suck up the water with a sponge and then let it dry out.

Looking at the BMW manual, it suggest there are two drain holes under the convertible stop frame mounts. I tried all kinds of ways to clean these out without removing the frame but because I did not know exactly where they were I never fixed it.

Today, I undid the frame mount on one side to have a look and lo-and-behold the drains are actually at each outer side just adjacent to the convertible top mounts. Attached is a picture of the left side drain with the frame removed. The bolt sticking-up is one of the lower frame mounting bolts, (there are two sticking up from the body and one nut and bolt that attaches the frame mount vertically) the picture shows the bolt towards the front of the car. Yes, BMW really put a drain hole in the most inaccessible point you could imagine.

Now I also found out why it got blocked up - well, I had the hood repaired some time back and I guess that in the process some blind rivets are used, because there were a load of the bits that come off when the rivet goes pop, hanging around the drain hole, together with bits of natural debris like leaves and of course mould making an nice waterproof seal. A quick blast from a compressor, plus I wiggled some of that plastic lawn strimmer stuff around inside the hole and then filled the locker with water and YAY the water came pouring out of the drain by the sills. The second picture is of the right side sill with water pouring out as it should.

So what I have discovered, is that you really DO NOT have to take the frame out to unblock the holes. Now that you know exactly where they are, you can use compressed air, a long piece of wire, or some of that plastic strimmer wire, whatever, but now you know where the hole is. I also found that a really bright hand held light helps see what you are doing because it is an a dark corner and almost impossible to see because of where BMW decided to put the holes.

I hope this helps someone.

By the way, forget worrying about trying to stop water getting in - water will ALWAYS get in, via the seals leaking, via the canvas becoming porous and even via condensation. Yes it helps not to have the seals not leaking, but even if everything is watertight, water WILL get in. If you doubt this, look how many drain holes BMW put in the sills, to ensure they let the water out.

Best wishes
Regards
Trevor
New Zealand





https://photos.google.com/share/AF1QipNnolCv20Pa8ZDJCTPpu18s0d2i3pnewRMD6leTRi1-gIrVB0FgY8y1jDDqbFnt0w/photo/AF1QipN9ikKmRxdHHnjtBc3lB4TTgKngZrTkBXbJn9v5?key=Z 1R4R21RVmxrSUZ0TV9iX25rS2RPcGVrV21WeHJR

[Trevornz]

Hello Folks,

I have searched the forums before to try and find out why my E30 convertible top storage locker (the space that the top uses when the top is down) fills with water and whilst some information has been helpful, I could not find anyone who had actually worked it out and actually fixed it with a clear description. After nearly a year of trying different things, I have now worked out exactly what is going on and fixed the problem. This posting is so you can benefit from that learning.

Problem - after rain, the convertible top locker fills with water, after heavy rain it is so bad you can hear it sloshing about as you drive. When it gets warm, the water evaporates into the car, causing it to get humid and everything goes mouldy. The only solution up until now was to open the locker and suck up the water with a sponge and then let it dry out.

Looking at the BMW manual, it suggest there are two drain holes under the convertible stop frame mounts. I tried all kinds of ways to clean these out without removing the frame but because I did not know exactly where they were I never fixed it.

Today, I undid the frame mount on one side to have a look and lo-and-behold the drains are actually at each outer side just adjacent to the convertible top mounts. Attached is a picture of the left side drain with the frame removed. The bolt sticking-up is one of the lower frame mounting bolts, (there are two sticking up from the body and one nut and bolt that attaches the frame mount vertically) the picture shows the bolt towards the front of the car. Yes, BMW really put a drain hole in the most inaccessible point you could imagine.

Now I also found out why it got blocked up - well, I had the hood repaired some time back and I guess that in the process some blind rivets are used, because there were a load of the bits that come off when the rivet goes pop, hanging around the drain hole, together with bits of natural debris like leaves and of course mould making an nice waterproof seal. A quick blast from a compressor, plus I wiggled some of that plastic lawn strimmer stuff around inside the hole and then filled the locker with water and YAY the water came pouring out of the drain by the sills. The second picture is of the right side sill with water pouring out as it should.

So what I have discovered, is that you really DO NOT have to take the frame out to unblock the holes. Now that you know exactly where they are, you can use compressed air, a long piece of wire, or some of that plastic strimmer wire, whatever, but now you know where the hole is. I also found that a really bright hand held light helps see what you are doing because it is an a dark corner and almost impossible to see because of where BMW decided to put the holes.

I hope this helps someone.

By the way, forget worrying about trying to stop water getting in - water will ALWAYS get in, via the seals leaking, via the canvas becoming porous and even via condensation. Yes it helps not to have the seals not leaking, but even if everything is watertight, water WILL get in. If you doubt this, look how many drain holes BMW put in the sills, to ensure they let the water out.

Best wishes
Regards
Trevor
New Zealand


https://lh3.googleusercontent.com/5w...=w1032-h580-no

[Trevornz]

I have tried 3 times to post my useful information, but I cannot get your forum to accept my posting, it keeps saying ATTENTION REQUIRED ! without any clue as to what attention.
Not being blessed with clairvoyance, I cannot work out how to make the posting work, suffice to say, I solved a really annoying problem with the convertible and wanted to help....

[Kershaw]

Well I see your post now.

[bobdavisnpf]

hmm, now I'm curious. Wonder what OP has on tap for us.
I just got my leaking top compartment fixed up. New top compartment flap seal from Pelican; new top from Convertibles Only in Seattle, with installation, leak detection, drain clearing, and installing the new seal.
Oh yeah, and new top compartment cover lifts, replaced those myself. I think some of the prior wear was due to the cover crashing into the mix when the top was being put up or taken down.

[Kershaw]

Does your top actually not leak at all anymore? Not by the forward top corners of the door windows? If so, that's impressive.

[bobdavisnpf]

Does your top actually not leak at all anymore? Not by the forward top corners of the door windows? If so, that's impressive.

Oddly, no. Front seal has been great, apparently - and it wasn't even replaced.
Unfortunately, front seal's the only thing that's held firm. Suffering a few months of Seattle driveway I figured out the car was leaking pretty bad from multiple sources, mostly the front drain and rear area of the top. Pretty sure that carpet, with all its integrated foam, had over a gallon of water in it. Once on a rack with heater & dehumidifier, it took a week to dry out. I've had the carpet and most seats out for months now - first to dry/recondition, then to find leaks, now to monitor while waiting for time and sun to align for carpet re-install.

[Ceekers]

I have had this problem also; The drains were clogged or partially clogged not allow the proper flow out from the compartment As mentioned some water will get in and for this reason the drains should be adequate. I experimented with a garden house to find out why I was getting water in the drivers side rear foot well and even under the rear seat cusion. If it there isn't enough access for water to flow out it will back up into the comparment and find another route to exit. So it goes into the foot well or under the seat. Make sure the drains are clear. Either run compressed air through the line or a plastic wire or coat hanger to remove blockage. One other things that has been over looked many time; If you notice there are factory stickers covering some of the access holes in the tonneau cover compartment. Two specifically are hidden under the convertible roof hinge where it mounts to the body. After some time these break and water then finds its way down. To fix this problem I removed the frame completely from the car removed the stickers; cleaned up the area with a solvent like brake clean and then applied a small plastic disk or equivelant and to make sure it wouldn't be subjected with perforation I also used a window urethan to seal it. I used a margerine top for the disks to cover the holes. I don't know WHY in BMW's infinite engineering wisdom why they would put stickers under the frame mount only for them to fail and cause water damage.

Oddly, no. Front seal has been great, apparently - and it wasn't even replaced.
Unfortunately, front seal's the only thing that's held firm. Suffering a few months of Seattle driveway I figured out the car was leaking pretty bad from multiple sources, mostly the front drain and rear area of the top. Pretty sure that carpet, with all its integrated foam, had over a gallon of water in it. Once on a rack with heater & dehumidifier, it took a week to dry out. I've had the carpet and most seats out for months now - first to dry/recondition, then to find leaks, now to monitor while waiting for time and sun to align for carpet re-install.

[KangstaE30]

Thanks for the informative post, OP. Fortunately I have not encountered this problem yet, have removed frame in past and didn't even notice the drains.

[Geraldine D]

My drains from the top locker have been blocked for years (with soggy carpets in the back...) - but i never knew.

Thanks to you and the photo i have now prodded around and cleaned bits and pieces away and water now seems to be coming out from the bottom of the car, so hopefully that is one of my many car problems solved!

Next problem to address will be the water pouring into the car via both front windows, but i'll leave that for a month or so.

thanks again