Tonneau leak

[Semblance]

I have an 89 vert, the tonneau compartment has been taking on water and then leaking from there into the trunk. I finally bought and installed a new gasket ($) this summer, and was pleased when it didn't take on water after the first rains last month.

But sure enough, it's leaking again! The gasket still seems in good shape, firmly sealed to its channel, and seems to contact the lid when closed. There did seem to be water on the INSIDE of the channel it sits in though at the top ... so did I F up the install? I used that 3M yellow stuff, it was a PITA to work with, though i thought i did ok. Is the water wicking somehow between the gasket and the channel? It didn't rain that hard or that long, but i had a half gallon of water in the compartment, seems like a lot for a wicking situation. Is there some other way for that amount of water to get into the compartment? There is a chrome trim between the plastic part of the lid and the sheet metal, but it's covered by the soft-top, and the soft-top gasket seems to be contacting the tonneau cover properly.

Really frustrated, any help would be appreciated!

[jeffnhiscars]

You dont say where the water is accumulating but possible sources are the tail light gaskets and the 3rd brake light.

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Sorry - the vast majority is accumulating in the tonneau compartment itself. From there a trickle makes its way down to the trunk. So it's not the usual - 3rd light, vents, antenna gasket, tail gasket - its not a trunk leak.

I guess what I'm really wondering is: did I use the wrong adhesive for the gasket, or otherwise screw up the install, or is there another possible leak source I'm not thinking of?

[jeffnhiscars]

When I replaced my gasket I used no glue at all so I doubt thats an issue. As long as the seal sits properly in the groove and there is ample tension on it, it should seal. The glue is just to keep it in place and is not part of making it water tight IMO.

I'm wondering if water can be sneaking past your rear window and trickling down the hinge. Its a long shot I know. I'd take a hose to a small area at a time to see if that can help you localize the source.

[Semblance]

Hm, that's a really interesting possibility. I know my botom window seal on one side is shot, never occurred to me it could migrate from there but I'll try to hose it down in small areas and locate it that way. Thanks for the reassurance on the gasket too!

[jeffnhiscars]

it looks like if the rear window seals did leak it would not enter the tonneau section. Other than the seal, which you say is new and well seated, it seems like the hinge area (where the shims are) is the only other way for water to get down there.

[Semblance]

Sorry to resurrect this thread, i havent had time to look at this more closely. Thanks for the great pic! Tried the hose and I think it's definitely coming in there, basically right where the gasket ends my soft top doesn't cover it well. But I've looked at other parked verts and they seem to be the same. I need a new top anyway so I guess that's a start. But in the meantime do you know if there are any drains in there that might be clogged? I think the e36 has tonneau drains, not sure about ours.

[Semblance]

So I found the drains - thought i'd share. As I said i needed a new top, got one yesterday from E30Jigzaw (thanks for the great deal!) and found the drains while cleaning the compartment during the swap. You'd never find them or clean them without taking out the frame. Here's a pic of the driver's side with the frame removed and all cleaned out:



The drain is the square black hole right in the middle of the pic with the cable running over it. The bolt a bit to the right is the forward bolt to secure the ragtop frame.

This entire area was covered in sludge. Cleaned it out, pulled a nice big lint ball from the drain (including a bunch of drilled out rivets from when the PO replaced his ragtop %^$^%#!!) poured a cup of water in, came out the bottom of the car. Good times.

[timmyr77]

I've been having the same leak for about a year. Couldn't figure out what it is. It would leak in there. Spread to the trunk and rear floor boards. I have a good top and also replaced the seal for the lid. So definetly gonna check this drain and hopefully that is the issue. Is it possible the drains at the bottom are clogged as well?

[jeffnhiscars]

Any drain can be clogged but I honestly do not think water should be getting in there and that those drains are there "just in case" and should not be relied upon

[jtparts]

Think about how the water behaves as you drive. It is being blown back off the car. So any place that has a forward facing edge is a prime suspect. The area just behind the doors at the latch are most prone to leak because any misalignment of the cover latches is most prominent there. Be sure to check both latches are holding the cover in the correct position. Of course if you are taking on water while parked, never mind.

[timmyr77]

Ya it's water everywhere while parked. I checked the drains. Pulled off the soft top today (needed to realign it anyways) and it was so dirty in there and the drains were more then plugged. Also found that there are holes throughout the boot for te top and the seals or stickers or whatever where all punched through and that's where water was leaking to the interior and the trunk poured a bunch of water in it after sealing all the holes and cleaning everything and there wasn't any water going to the interior or trunk. All of it gushed out of the bottom. Thanks OP for starting this thread. This helped a lot. That leak was the most annoying thing about my car!

[Semblance]

This was absolutely the source of the leak for me. It took on a lot of water when parked. I don't have pics, but at the front of the tonneau cover, between the cover and the body trim to the front, there is NO SEAL. (You can see the area in Jeff's picture above, where the trim on the body stops at the tonneau cover). Water just drips in. This is right above the drain too, so if the drain is working, the water goes straight out. Confirmed with a garden hose test as well. No water in there since I cleaned them out.

Timmyr77 - I think they probably could be clogged at the bottom too. When I was researching it seems that this happens a lot on sunroof drains.

[Semblance]

Glad that worked out! I hated that leak too.

[timmyr77]

The bottom wasn't clogged at all. I took out the rear interior to check and in the borrow. Water came out fast and cleab