So, I can't complain because I practically stole this car from its former owner, BUT I don't think he did anything other than change the oil during the 5 or so years he owned it -- certainly not judging by the condition of the leather. And also by what I just found in the trunk: About 1-2 inches of standing water around the spare and -- yes -- the battery. And it's not a recent development (which is good, in a way: I know that if I nip it in the bud then it shouldn't cause any new problems) -- there's LOTS of accumulated rust and corrosion on the spare's rim, and the entire well is stained with rust. On the other hand, it didn't rust through, so it may not have been THAT long. First question: could it be as simple as the trunk seal? There's definitely damage to it at the lowest point. Also: the water hardly drains (I had to leave it overnight after finding it), so presumably it's not coming in from below. My only worry is that it's coming in somewhere behind the battery (i.e., the right rear wheel well) -- due to a lack of a 13mm wrench and a good deal of corrosion I couldn't remove the terminal connections and thus couldn't get a good look behind it. Second question: anyone else heard of or personally experience anything like this? I'm still amazed that it didn't cause any electrical problems; it rotted away the cloth wrap on some light wiring, but that seems to have been the extent of the damage. Oh -- obviously, I've removed the water, swabbed as many surfaces as I could and sprayed the whole compartment down with WD-40 as a stopgap. I'm thinking naval jelly or something like it next, unless anyone has a better idea. Thanks for your help!
The trunk lid gasket is one place to look. Water in a BMW trunk often comes from bad seals around the taillight assemblies. Is the rear window properly sealed?
Thanks for the reply -- it looks like the answer is "no" to all of the above. I'm going to pull all of the trim off the inside of the trunk this weekend and try to track it down (not to mention air it all out).
I had a Range Rover that took on water in the trunk. To remove water you have 2 options, my personal favorite is look for a removable plug (Rover had one) pull the plug out and let water drain, leave it out till you resolve the leak then put it back in. The other option which i did to a 924 Porsche was Drill a 1/4 inch hole in the lowest part and let the water drain out of it. Either one will do the trick for water removal. Here is the fun part. How to find the leak. I use one easy method but it requires 2 people (one should be small.lol. Get in the trunk and close it (make sure you have a flashlight) have the other person spray the tail lights with water from a hose see if intrusion is there, the spray the trunk area down with pressure and see if it gets wet. That easy to do and hopefully the person will let you out of the trunk afterward. 9 ouut of 10 times it is the trunk seal that is the culprit in my experience (my old Porsche 928s4 loved to leak from the seal) I hope this helps
I do not know where the rear sunroof drains are located on an E36 sedan but I had one come loose on an E30 and it flooded the battery tray area. You may want to look for the sunroof drains and make sure they are still connected and working as they should. Matt
