It rained hard yesterday, with a lot of wind. We had seen a leak into the trunk before, and sure enough, there was one again this time. When examined at noon (around 10 hours after it stopped raining) there was water under the spare - and nowhere else. The sides of the trunk the removable mat (both sides), the metal leading down to the bottom, the upward facing part of the spare, the trunk lid were all bone dry. This is a 1998 Accord EX (4 cyl ULEV). So I poured pitchers of water all around the open trunk, outside the rubber seal, and over the taillights that are part of the body, and all around the sun roof. Not a drop entered the trunk. I could not test the lights in the trunk lid the same way, but that should have dripped onto the removable mat, and that was not wet. In the picture below the points with little bits of wet paper towel were wet, but no other areas. There was no obvious trail left by water running down into that spot. Is there some bizarre way it could have come up from below?

Anyway, not an obvious leak. Suggestions?

Thanks.

 

I have a similar issue so i'm interested in hearing what people think.

 

I had a similar problem once. Turned out to be the seal around the tail lights. 94 Accord EX.

 

How were you able to re-seal them?

 

Actually I replaced them with custom tail lights. I found the leak when I was doing this. It seems that just using some gasket sealer around the housing and gasket would work. If that's really your problem.

 

I may have found the problem.

Removed the plastic shield at the back of the trunk around the latch and pulled out the liner on both sides. (Note 1: To remove the round push pin type retainers place a pry bar between the liner and the metal behind it. Prying from the inside of the trunk ripped the head off one. Note 2: The retaining pins on the side trays are a PITA to get out. I had to use a pair of bent picks to reach under them and lift them up. Careful - they tend to fly away when they come out.)

On each side of the trunk there is a large diameter clear hose which drains the back of the moonroof. Each goes into a rubber "sock" which passes through the side of the car to drain somewhere in the wheel well. A long funnel was placed in each sock and some water dumped in. The passenger side drained out, but the driver's side only drained partially. So what probably happened was that the water backed up around the tube and out of the sock, and then down into the trunk. There was, however, no sign of it there. The driver's side sock was pulled out and cleaned thoroughly under running water. Since the other was already draining well, I just pushed a zip tie through and run a lot of water through. Then reassembled everything. It was not easy putting that sock back in. It has a sort of grommet configuration where it goes through the metal, and it was necessary to shove the outlet side through the hole with a small screwdriver, while rotating the "sock". Once it is properly reinserted it rotates fairly easily, but when only partially inserted it is stuck pretty tight. I left a half piece of paper towel under/near each of the socks. If water is found in the trunk hopefully it will be clear from those if the water was coming from the socks.

 

So, that initial repair leaked in a big rainstorm. However it was clear that the leak was from that general vicinity because the paper towel on that side was wet and the metal near it was slightly damp.

Pulled the tube out of the sock, and the sock out of the metal. Ran a tube through the hole and poured several gallons of water through. Initially big chunks of mud and debris came out, and then eventually clear. (The idea being that maybe the outlet was in a pocket of some sort and it was draining slowly enough that water was backing up.) Put the sock back into the metal, and the tube back into the sock. The tube felt a little loose in the sock, so 3 zip ties were applied around the outside of the sock to form a sort of hose clamp. A real hose clamp would have been better, but I didn't have one that small. Put in a new paper towel and reassembled the rest of the trunk. (A better fix if the tube is loose in the sock would probably be to get a replacement sock.)

A couple of days ago it poured rain, like several inches, and the next day the trunk was bone dry.

So, success, I think. However I have not definitively ruled out the possibility that the tube is loose at the sunroof, so that water might drip down the outside of the tube. No drips into the rear seat or discoloring of the liner though. Still, if the car this time happened to be tilted towards the other rear drain it might have all drained out that way and not really tested this round of repairs. It is also disturbing that I was not able to replicate the problem initially by pouring a lot of water onto the sunroof. Perhaps the seal only leaks when the rubber is sufficiently chilled?

 

Still not fixed. Sometimes it leaks sometimes it doesn't. We never use the moonroof, so however the glass has fit into the rubber seal around the edges it is the same both when leaking and not leaking. I pulled off the headliner and found all 4 tubes firmly attached. Retracted the moonroof and poured about a cup of water at a time in at various points. It poured nicely out of spouts in the wheel wells at the appropriate corners. There was one slight sign of trouble. If water was poured quickly into the passenger side channel with the car slightly tilted nose up 99% of it would slosh through the tube rapidly and then a few seconds later a few drops would come out underneath the white piece of plastic to which the tube is attached. There was no water mark on the top of the headliner there though. The only water marks are at the front driver's side tube clamp point, and that is old, because when the car had body work long ago they forgot to reattach that tube. One of the first things I fixed after we got it. Perhaps that piece of white plastic needs to be resealed to the back of its channel? Probably have to drop the whole thing down to do that though. Unhooked one tube at a time and ran a long zip tie down them - no blockages were encountered.

Just for fun the carpet near the driver's seat is getting wet right near the sill. It cannot be that back passenger side couple of drops, since the car is always parked with the driver's side front wheel highest. That is, water should drain towards the right and back. I have observed a few drops clinging to the area around the hood release lever, but it is always bone dry everywhere I can reach above and forward from that. I can see the tube going into the boot at the firewall, and no sign of a leak there. The angle of the boot is pretty flat though, at least compared to the ones in back, which are close to vertical.

I'm beginning to wonder if the front and rear window seals might be starting to fail.

 

I noticed water in the same area after I got my 97 Accord repaired due to a rear end crash. Had rear panel replaced and used OEM taillights. After I noticed water leak, I traced it back to the gap between the rear panel and tail lights. I sealed the gap with plumber putty and the leak is gone since.

 

Thanks, which gap are you referring to? The gap between the actual metal and the taillight housing? or is it the gap between the trunk/boot lid rubber gasket and the taillight housings?

 

The low cost body shop I used to replace the rear trunk panel did not align the driver side taillight leaving a small gap between the metal and the tail light rubber gasket. When water runs down the channel on the edge of the trunk lid used to get into the trunk. I think the tail light housing was not seated properly leaving some gap for the water to seep through.

 

When this all started I sprayed the taillights with a hose and then poured a lot of water onto the trunk, and later directly onto the channel outside the rubber trunk lid gasket, both sides, and it didn't leak. I suppose it is possible that since then something has opened up in that area. It won't hurt to try it again.

People also report that sometimes the junction between two pieces of sheet metal, which is factory sealed and runs down the center of that channel, can leak. The fix then is to scrape out the factory sealant and apply something like silicone to replace it.

 

I took off the roof liner and had my wife pour water in the channels while I watched from the inside. There is a leak on the rear right hand side, near the drain hose, but not from the drain hose. The metal 3 sided channels (like a U, but rectangular, in cross section) run front to back and at the posterior end are sealed with some sort of plastic like hard material with a fitting for the drain hose to attach. Well, that plug of material has somehow detached a bit from the channel, which lets some water out. That plug material is very hard and has no give at all. It's dark, but feels like acrylic. (Not saying that it is acrylic, just that it has a similar feel.)

Any thoughts on how to seal that?

The front leak may be the drain line from the sunroof working properly, but emptying onto the hood release cable, and then running own that and into the car. The water seems to enter the car right at the release lever. The temporary "fix" has been to stuff a sock in around the lever, and that absorbs all the moisture, so long as it isn't a sustained downpour. Also, parking in the driveway with the nose pointing uphill should help with the front, albeit at the cost of making the back leak worse.

We never use the sunroof, sealing it off would be OK.

The clear coat is failing on the roof, coming off in big chunks in some areas (which was repainted after a tree tipped over and dinged the roof slightly on the driver's side.) I don't think vinyl can go onto a surface like that. Maybe I should sand it a bit and plastidip it? That will be pretty ugly, but then, it already looks pretty rough. Pretty sure painting flexseal all the way around the opening would solve all of this, but the wife would never accept a repair that hideous.