Z3 Roadster (E36/7) Water found under drivers side carpet?

Howzit going!

Yesterday I replaced my seat bushings. While I was at it, I cleaned up the carpet areas. Anyway, I discovered water under the drivers seat carpet, soaking the foam as well as creating some rust spots. Lame! Interesting the carpet exterior was dry.

I found an old sopping wet paper towel under the area, telling me that the previous owner knew about the water. And also found a loose black rubber 50-cent sized grommet with a pencil sized center hole. I couldn't identify where that came from. It has a lip, as if you could use it to snap over/cover something? Maybe from the seat?

And, we have had some rain recently...

Question:

Any one had this happen before? Where might the water be coming in from? I'm thinking there may be a hole on the undercarriage taking in water? Maybe from the side or back seam of the soft-top?

Any ideas?

Thanks,

TC

This is very common and is probably caused by one of several sources: A-pillar leak, door seal leak, window leak.
Near the top of the page, on the right, is a button called "Search This Forum". Click on that and type "leak" or "wet carpet" or "A Pillar" or "water" etc. and you will find many threads with complete instructions of where to look and how to fix each.

Thanks for this...

Interesting, so this may be coming from up top or from the sides, not necessarily splashing up through the under carriage etc...?

Ok, Im going to check all those areas.

Mahalo,

TC

Originally Posted by tcesar888

... so this may be coming from up top or from the sides, not necessarily splashing up through the under carriage etc...?

Most unlikely to be splashing up from underneath. More likely from the rubber seal between windshield and soft top, or from the seal between rear of soft top and body, or plugged drains on each side of the boot, or from the rear window. Here are some threads...
http://forums.bimmerforums.com/forum....php?t=1308616
http://forums.bimmerforums.com/forum....php?t=1365003
http://www.zpost.com/forums/showthread.php?t=63033
http://www.bimmerfest.com/forums/sho....php?p=4739195
There is also a thread with photos about the water channels and rubber plugs in the ends of the windshield seal, that can conduct water down to the sills and floor, but I can't find it.

Here's another, but not the one I am thinking of:
http://forums.bimmerforums.com/forum....php?t=1816807

Thanks Vintage42!

My first "guess" is that it coming in from the side and rear body seam of the soft top. I have to take a closer look. If water gets in there, is there a drain to move the water out?

I'll check out these links learn more.

Thanks again!

TC

There is a drain on each side so normally a leak there will not run into the cabin. It's a very common place to leak, usually from a cracked sealing frame, but water will run into the trunk from there.
My personal experience is that the inner door seal leaks allowing water to run behind the door panel and over the rocker panel.

Interesting! So water maybe entering through the doors? Meaning the rubber that that seals the door to the body "might" be leaking? I was thinking of replacing those, to tighten the door closure etc.... But I didn't think water would be coming in. Unreal!

Do you think I need to (or should) pull off the door panels?

Thanks,

TC

Certainly those could be leaking. That would be easy to diagnose with a pitcher of water.

But I was referring to the seal behind the door panel. You can remove the inner door panel to reveal a plasic or foam skin (depending on model year) held in place with butyl tape. That tape often fails and allows water to drain behind the inner door panel. You might be able to detect evidence of water below the door panel, paricularly with the door open.

There are other sources; do a search.

Blacklane,

All great information. Do you think water from this door seal area would find its way under my seat and floorboard? Just curious.

Thanks again!

TC

Yes. When the door is closed, the water can run right over the plastic sill and into the carpeted area, at least it did on my car.

Originally Posted by Blacklane

Yes. When the door is closed, the water can run right over the plastic sill and into the carpeted area, at least it did on my car.

I am confused about two things. Are we talking about the rubber door gasket, or the internal sheet plastic behind the panel? And for the sill, water cannot be running uphill over the sill, but must come from above the sill. Is the steel bottom of the door above the sill, so if water collects in the door, it drains out over the sill into the car? (I am a thousand miles away from my Z3 today).

If the inner door seal has failed, water will enter the car behind the inner door panel about half-way up the door. Then run behind the door card (the big leather-looking part of the door) unseen. Then it will then be above the door sill, inside the car, and then run into the carpet. It wasn't obvious to me unitl I removed the door card.

Obviously, the roof could be leaking, the a-pillar could be leaking, and/or the elephant hose could be leaking. Those require different trouble-shooting.

Originally Posted by Blacklane

If the inner door seal has failed, water will enter the car behind the inner door panel about half-way up the door. Then run behind the door card (the big leather-looking part of the door) unseen. Then it will then be above the door sill, inside the car, and then run into the carpet...

OK then,by "seal" you meant the plastic sheet not the rubber gasket. the OP should take off the door panel and check the plastic sheet.

On earlier models it is a plastic sheet (called a "foil" on RealOEM.com). On later models it is a foam sheet (called "sound insulating" on RealOEM.com). They are both held in with the same butyl tape, which is also the same sealant used on the convertible top.

Butyl tape gets brittle with age and causes leaks.

If you do a search on "wet carpet" you will find dozens of threads (see post number 2 above). This is one of them. Look this over. http://www.bimmerfest.com/forums/sho...d.php?t=670179

Wow, great info. I need to pull off my door panels and check out the seal.

So if I may summarize...

1.) Water runs down my window entering and filling up my door with water...
2.) Once it fills to a certain level, it overflows...
3.) If the plastic, foam, or cardboard inner door seal is old etc.. the water can spill over...
4.) The spill will enter the car at the base if the interior door panel and fill up my carpets...

I dumbed it down a bit, how does that sound? Lol.

I realize the leak could be coming from another spot, but it this makes perfect sense and I'll check it out tomorrow.

BTW, you mention "elephant hose" where is that located? How do I check for that?

Thanks again!

TC

That's pretty close except the part about the door filling with water to a certain point. The water enters at the window seal, runs down the inside part of the hollow door, reaches the holes for access to the window motor, latch actuators, etc. These holes are covered by a big piece of plastic glued onto the door with butyl tape. But the tape fails, allowing the water to to the inside of the steel door, behind the door card. It then runs down the door and into the car unseen.

The elephant hose is more precisely known as the cowl drain. It drains the vents below the windshield. If it is clogged, water will build-up and overflow into the heating/air conditioning system and soak the carpet under the dash.

Here is a picture of the cowl drains, also known as "elephant hoses." They are on the firewall behind the engine. Since I have my transmission out, they are easy to see from the bottom. Normally that is not the case.

Super!

I have my weekend project.

Mahalo!

TC

Originally Posted by Blacklane

Here is a picture of the cowl drains, also known as "elephant hoses." They are on the firewall behind the engine. Since I have my transmission out, they are easy to see from the bottom. Normally that is not the case.

How are the hoses accessed for cleaning -- from above in the cowl, or from below with the car raised?

To clean the cowl drains, you remove the panel between the hood and the windshield. I just posted the picture from the bottom so you could see the hoses and understand what they are.

Originally Posted by Blacklane

To clean the cowl drains, you remove the panel between the hood and the windshield. I just posted the picture from the bottom so you could see the hoses and understand what they are.

Can you see the cowl drains from above without removing the panel?
If not, would it be a good idea to remove the panel to check and ream out the drain tubes, if it has never been done before, to head off any potential overflow into the car?
Is there a DIY on how to remove the cowl panel?