New E39 owner 2000 M5 soaking wet

[alabbasi]

All, I recently purchased a 2000 BMW M5 that i've been slowly fixing up. I live in DFW Texas and it's been raining pretty hard the last couple of weeks. Yesterday evening, I took the car for a spin and noticed that the rear floor boards were soaking wet. Any ideas on how the water is getting in?
I also have a non functioning Nav radio. The NAV portion works, but the radio does not have any sound. I also have a few other issues that I need to address, most importantly raising the suspension as it's on coil overs and scrapes on just about every bump on the road.

Many thanks and apologies if these seem like basic questions. I'm mostly a Mercedes Benz guy but have a couple of old BMW's also including an E39 540i/6 that I bought two years ago but have not driven because it sounds like the engine is about to self destruct and I suspect the guides let go.

Here she is next to her 2002 E55 stablemate.

[sealbeach740]

Wet rear floors are a very common problem with the e39. Search on this board, or just the internet for vapor barrier. The rear door card's vapor barriers tend to come unglued on the bottom corner & leak water. Many different ways to fix 'em, you can pick the one you like/trust best.

[edjack]

The rear carpets are no doubt caused by a failed vapor barrier behind the door card. Make sure the passenger carpet is also not wet. There is a power distribution under the seat, that will corrode and cause many problems.

Looks like you are a German car masochist.

[jclausen]

You might as well check all the vapor barriers, who knows what condition there in or what kind of adhiesive they used.also I would remove the cabin filter assays and clean them out also the cavity that the master cly sits can fill with water also. You might have to remove the seats, lift the carpet and put a fan on the carpet if it's really wet. Check your sunroof drains too.

[crazy4trains]

Fix the vapor barriers. Remove the rear seat (bench). Then pull up as much of the carpet as you can to expose the foam underneath. It is very thick and holds a lot of water. Rent a dehumidifier, close up the car and run it over the weekend.

[alabbasi]

Looks like you are a German car masochist.

Ehem, German and British car masochist

Thanks all, I did a search on the forums and found several threads on the vapor seal. Hard to imagine that so much water can come in this way as the carpets are pretty darn wet and the car has just been sitting. I will remove the back seat and get behind the carpet today. I have a pretty powerful shop vac so it should get most of the water out. The rubber trim piece around the windshield is also perished which may or may not cause a problem. I already have a replacement.

I did remove the cabin filters and inspected them, they were fine. I actually bought the car from the previous owner with non functioning brakes. He replaced the master cylinder and could not get the brakes bled. We initially thought that there may have been an issue with the ABS module or computer but after spending some time with it after I bought it, I figured out that there is a special procedure to bleed the ABS pump that required the use of my Autel scanner. Once I bled the brakes correctly, they function fine.

[JimLev]

Check the front pass carpet too.
Under it is a big fuse block, if it gets wet and corrodes you'll have plenty of electrical problems.

[alabbasi]

Check the front pass carpet too.
Under it is a big fuse block, if it gets wet and corrodes you'll have plenty of electrical problems.

Front carpet is dry, thanks. It's the first place I checked as there is a similar problem with my my S55 where leaves block the drain holes that can cause enough electronic damage to total a car.

[computiNATEor]

Front carpet is dry, thanks. It's the first place I checked as there is a similar problem with my my S55 where leaves block the drain holes that can cause enough electronic damage to total a car.

Remove the carpeting trim and lift it up by the front passenger seat to make sure it's dry. The foam insulation hides a TON of water.

The front windshield seal - the one that you can see - is not a weather proof seal. That's mostly there for aerodynamics and wind noise. The windshield is glued in with urethane, which is where the water is stopped.

Since it sounds like you have plenty of other vehicles to use, I'd recommend removing the entire interior - seats, carpeting (carefully cut it under the heater box assembly), door cards, etc and let them fully dry - and sit in the back and have someone run a garden hose over the exterior.

[geargrinder]

Remove the carpeting trim and lift it up by the front passenger seat to make sure it's dry. The foam insulation hides a TON of water.

This.

[alabbasi]

This.

Thanks, I took the car to the shop today and left it there. I also picked up some of that GE black silicone from Lowes. I'm a big fan of the clear stuff. FYI, nice 107, here is mine

04232010008.jpg

[geargrinder]

Ok. Some guys have failed w silicone / RTV in this application but some make it work. Cleanliness is the key and I think the silicone might not like the residue left behind by factory butyl, making it more work to clean than using butyl again. If I was to non factory I'd prob go all the way to 3M urethane (which is mega sealing and less picky, but near permanent if you have to get in the door again) and not RTV / Silicone.... But... I guess some guys have gotten it to work...

My R107 is sadly long gone, times I miss it but mostly it's a relief due to too many cars and never being able to do all the repairs I wanted...