wet carpet on driver's side floor
 

We had a real downpour last night, and while I was in the X5 testing android apps & peripherals for my "gauge substitute" project https://xoutpost.com/bmw-sav-forums/...le-gauges.html, I noticed the carpet underfoot was wet. Despite having several such storms during my brief ownership period (5 months now), there have been no other leaks.

The carpet shows signs of water draining down from behind the dead pedal; I'll try to remove it to see what's behind there.

I've never used the sunroof, and removed the fuse for it previously, so there's been no movement of the glass up there, so likelihood of suddenly developing a drain leak (along the front left A-pillar, which shows no moisture) is low, IMO.

I did disturb the firewall plug above the footwell when running wiring for my electric fan installation, but I sealed it thoroughly with pest-proof Great Stuff foam spray, months ago. No leaks before now, and the carpet on the toeboard is dry, directly under the plug, and the firewall area was completely dry underhood, on both sides, as well.

I also checked the drivers door drains and the sill area; no moisture anywhere, either, and so I suspect another area...the bottom of the windshield where the seal meets the body.

On both sides, the seals meet at a crack/hole that seems a logical drain to me. Mine were filled with tree debris (X5 sits under oak trees), and were wet, still. I'm unfamiliar with the bodywork, seals, drains, etc. on this vehicle, but might my wet carpet originate with the left side "drain" hole? My X5 sits tilting forward and to the left, making most drainage flow in that direction. I blew all debris clear before taking photos:

Attachment 81057dry toeboard next to dead pedalAttachment 81058door drain and door sill area both dry

water inside dead pedal and under front half of sill plate
 

Pried off the dead pedal and found standing water in the bottom bolt hole; the top bolt hole was dry. Now I'm attempting to remove the driver's side kick panel, but it's a bear (unlike those on my old project cars from the 50-60-70-80's...one or two screws and they popped off). Anyone have a how-to? or do I just wing it and hope nothing breaks (it's 20+ year-old plastic, you know).

There is a common issue with the drain that goes from the roof window getting blocked. It's almost always why water in the footwell.

Please pull the A-pillar plastic and have a look at sunroof drain..It's one bolt...Make sure the drain hose is still in its metal tube near windshield.

sunroof drain tube? why hasn't it plugged up before now?
 

I saw this while searching earlier https://xoutpost.com/bmw-sav-forums/x5-e53-forum/101904-diy-e53-sunroof-tube-kink-fix.html
and this https://xoutpost.com/attachments/x5-...roof-drain.pdf, which should walk me thru it, but is there anyway I'd trigger an airbag while in there, or should I disconnect the battery? Remember guys, I only have one key with two generic remotes; I hesitate disconnecting power to the EWS until I get another genuine key...my battery is under a year old, and kept on a maintenance charge 24/7.

Also, should I keep trying to remove the dead pedal/driver's kick panel to locate the leak, or just clear the drain tube? I have a lot of .155 trimmer line, so should I skip ahead and just shove it up the tube first, or use compressed air if it won't go very far in?

Question: is it common for a drain tube on a seldom-driven/never-driven car plug up out-of-the blue? According to the previous owner, the sunroof never was used/never leaked for 3-4 years before I got it from him 5 months ago. I guess it's possible....

For me it was the drain tube in the a pillar as mentioned above. Somehow, someway the rubber drain tubing pulled out of the metal tube built into the a pillar and leaked water down into the driver side foot well. I removed the foot rest/ kick panel and vacuumed as much of the water out as I could.

I have two facelift E53's and therefore four A-pillars...I have encountered a leak, or kinks (resulting in a drain blockage) at all four of them...

I never use the pano sunroofs..

Because the A-pillar leak is so common, I would pull the A-pillar before I pulled the dead-pedal trim.

I can't explain why exactly, but the rubber drain hose has just enough slack to move around and often pulls itself out of the metal drain tube...I don't know if this only happens in freezing weather or not. The solution is to zip tie it so that it has less slack.

I do not disconnect battery when pulling the A-pillars. Yes the airbag is there but don't go near its connector.

You can buy a rubber tipped air nozzle from Harbor Freight for a few dollars and a cheapo regulator for about the same price that regulates down to under 10 psi.
If you also get a press fit to 1/8" pipe thread hose connection from your local Parker distributor and a couple feet of nylon hose, you can make a tool to test the drains. You screw the 1/8" fitting in to where the interchangeable nozzles go. Use very low PSI when you do the job. You can also use the tool to blow air up into the two drains next to the transmission that drain the AC condensation reservoir that has caused the wet carpet in my 2001 several times.

preventive airbag procedures, preparing for rain event
 

I never go near airbags If I can avoid them; a friend set one off years ago, how he did it unknown, but it made a mess of his dash that he never repaired. So, I couldn't sleep last night, and looked up fuse positions for airbags & SRS (clockspring in the steering wheel):
And I looked up fuse locations for Airbag diagnostic module #44, and steering wheel clockspring/contact ring #29, from two sources (not the list in the X5...it was 3am). So, just to be "safe", I'll pull those two fuses before I pull the A-pillar panel.

It might be awhile before I can do the work: jacking up the X5 enough so I can feed trimmer string thru the drain port underneath, removing airbag fuses & A-pillar panel, un-kinking/un-plugging the suspect drain hose, and the re-assembling dead pedal and A-pillar (after testing). I'll be working in the dirt/sand/gravel/leaf debris that the X5 is parked on, and it's supposed to start raining for three days, starting in about 2 hours, so I'll probably get little done. I'll cover the sunroof with a tarp, in the meantime.

I intend to buy four 4'x8' pressure-treated 3/4" thick plywood sheets to make another work area just for the X5...I have smaller versions of the same under two other vehicles already, the plywood lasts for years (but plywood prices rose too high to do so over the summer...now that the prices are lower, I can get the sheets, soon).

to blow out clogged lines
 

I'll order some rubber tips for my airgun; I have some nylon hose and some fittings that might work for the test assembly, already. Good idea!