VERY Wet Passenger Floor Area

[bmwman91]

First, yes, the elephant trunk is clean and clear, as is the area around it where water flows.

I got home tonight and noticed that the car's windows were all fogged up...from the inside. Never a good sign. We had a very heavy day of rain yesterday, and it would seem that the passenger footwell is SOAKED. I reached up in front of the glovebox, and the yellow padding stuff up on the firewall is also soaking wet, so the leak is somewhere up there. I have seen mention in very old posts about failed seam sealer between body panels or something around the fender. Does anyone have any suggestions for where to start looking? I am going to try to yank the carpet tomorrow morning so that I can start drying stuff out and avoid rust/mold. As thankful as I am for the rain...I don't want any more until I can figure this one out!

[Jaxx_]

Is the elephant drain clog free?

[bmwman91]

Yes, it is clean and clear (see first sentence of first post).

I pulled the car into the garage and yanked the interior tonight so that everything can start drying out. The carpet sure holds a lot of water lol.

Poking around, it seems like the highest wet spot in the yellow firewall padding is right under the entry for the main ECU harness. That is certainly not leaking, but there is a big horizontal "box" all above there which is part of the battery tray, at least on the outboard portion. After pulling the passenger air inlet grille, it does look like the body sealer that runs along a seam at the bottom of the area is cracked, which (I think, need to confirm) would let water run down to the interior portion of the battery tray shelf. So, I will need to push the car out and experiment with the garden hose a bit to see if I can confirm it is coming from there.

The outermost stud (of the three) that nuts hold the glovebox door is missing entirely, leaving an open hole into the engine bay. As far as I can tell, my hood gasket is fine and water is not getting to the tray, but if water did get on there, it would run right in. Some RTV is in order there...

I will try to get some pictures of the cracked seam sealer tomorrow. This isn't really what I wanted to spend my evenings messing with this week. Doubly so since the existing seam sealer is really dirty, hard to access, and I am not sure what the right way is to go about repairing it. It almost seems like something I would want a body shop to do. We'll see...

[tomstin]

A few things to consider. The Elephant trunk can be overwhelmed, water also needs to drain out behind the fender. Make sure that area is clear. The boot that goes around the AC hoses as they go through the bulkhead can break down and leak into the cabin. Also the heater box has three drain tubes, they crack and tend to leak under the carpet. And of course, the sunroof drains. Also, make sure the rocker drains are clear, water can back up in them and run into the cabin in the craziest places.

[bmwman91]

Thanks, I will check those out and see if I can run some weed trimmer string through the tubes in the various areas. I'll try to get pictures of everything, too.

[bmwman91]

I think that I have found the issue. Water gets past some plastic expansion anchors that hold the rubber sheet onto the firewall on the passenger side, runs down into the battery tray, and flows in through a hole created by a body stud that tore out. Some experimenting on the car in the driveway with the garden hose confirmed this. Additionally, the AC hose grommet lets a little water in, but I have to blast it with the hose to get any water past, so I do not think that it was leaking at all during the rain storm since the only water getting down to it was from one of the expansion anchors.

Photo dump time...

The little glowing hole in the middle looks right down into the passenger footwell. It is where there WAS a threaded stud welded to the body, which got torn off at some point in the last few decades. Any water that gets in there will run right down behind the carpet, which is why I have not noticed this for so long. Years of not-much-rain and not driving the car much apparently had this flying under my radar. Luckily, there is no rust that I can find in the floor pan and no mold in the carpet, so thankfully it would seem as though water was not entering in large quantities in most cases.




The missing stud on at the right is where that hole is. Water was getting into the yellow padding and running down behind the carpet for the entire day last Sunday when we had a ton of rain.




So...testing. This puddle of water on the battery tray is from water running over the expansion anchor in the next photo.






This puddle is from a mix of these two anchors (there is one sort of hiding in the shadows to the right of center).






And lastly, this bit of water is from the outermost anchor.






I shot the AC hose grommet full-blast for a solid 20 seconds, a little water made it into the car. I don't think that this is really a problem compared to the other hole, but I am going to replace the grommet anyway. There is no AC in the car (hasn't been for a decade) so it will be easy to do.





I had also noticed a bunch of cracking in the seam sealant lines in the cowls. While it is not a good thing, I do not believe that it is allowing water into places that it does not belong. Nevertheless, I am going to scrub the crud out and fill the cracks with either RTV or some sort of automotive sealant if I can find the right stuff. These photos are from the passenger side. I noticed a little bit of the same thing going on in the cowl area of the driver side as well.