Under Cowl Drain Missing? e85 Z4M Water Leak

[SaltyNC]

I recently purchased a low mileage, one owner, 2006 Z4M. The car was sold, I believe, because it has a leak under the carpet on the driver's side that couldn't be resolved. I think I have found the source of the leak, but I need confirmation. I'm hoping someone will do me a huge favor and check to see if you have a rubber drain in a particular location.

Under the plastic cowl, near the center of the windshield, is where the wiper motor is mounted. Under the wiper motor is a drain. I believe there should be a rubber or plastic grommet with a rubber drain pipe that fits in the drain. On my car, that drain tube and grommet are missing. I think it was left off when the car was built. Instead of a drain, I have a large silver dollar sized hole in the metal. A cutout in the firewall material rests against the underside of this hole. My hunch is that water is flowing out of this hole and flowing between the metal and firewall material where it makes its way under the carpet in the driver's footwell. The firewall material felt damp when I ran my finger between it and the metal of the cowl area.

Below is a picture (sorry it's dark and rainy here today). This is looking along the driver side brace and brake fluid holder. The arrow is pointing to a microfiber towel I have pushed down into the cowl drain hole.

The favor: Can someone look in this area on your e85 Z4 and tell me if you see a small black drain tube where the grey towel is located? If possible, a picture of this same area on your Z4 would be very helpful. Thank a million!

Below is a link to the parts I think are missing. #8 and #9.
http://www.realoem.com/bmw/enUS/show...diagId=64_1365

[Steeler]

http://www.zpost.com/forums/showthre...&highlight=Wet

Try this thread for info

[StickMon]

The picture from realoem is deceiving.
#8 and #9 are actually in the tunnel above the transmission.
That's where the A/C drains onto your transmission mounts.
(Thread on that somewhere, too).

I think it's #3 that you may be missing.
I know that mine ends near the aux air pump on the passenger side, with a little rubber flap over the end and usually some leaves hanging out, but I never really looked to see where it begins.

[SaltyNC]

Originally Posted by dbarton62

http://www.zpost.com/forums/showthre...&highlight=Wet

Try this thread for info

Thanks, bud. I had read that ordeal. In fact, I've read ever leak thread on the internet, I think. I believe mine is different. I think it really is missing a drain plug under the cowl. I wish I had taken a pic with the cowl off. I have the parts ordered, so I hope it will be the right parts. The illustrations on RealOEM aren't super clear for this area, but the elephant nose drain shown in the link in my original post is under the cowl, so I hope the other parts are correct and in this same area. I have the elephant nose drain in-tact. It's the small one that I think I'm missing.

I've already had my seat out and the carpet pulled drying it the first time. I thought the water may have been from the dealer being overly enthusiastic with a pressure washer when prepping the car, but it leaked after I washed it with a garden hose.

Thanks again for the link.

Salty

[SaltyNC]

Originally Posted by StickMon

The picture from realoem is deceiving.
#8 and #9 are actually in the tunnel above the transmission.
That's where the A/C drains onto your transmission mounts.
(Thread on that somewhere, too).

I think it's #3 that you may be missing.
I know that mine ends near the aux air pump on the passenger side, with a little rubber flap over the end and usually some leaves hanging out, but I never really looked to see where it begins.

Stickmon, thanks for this info. Dang!! That stinks on parts #8 and #9. I thought I found the parts, but it sounds like I haven't. I've seen pictures of under the cowl under the wiper motor that has a rubber drain grommet where I have an empty hole, but I can't find the part listed anywhere for that rubber grommet. I have the elephant nose drain #3. It begins under the cowl on the passenger side, so that one is in place as it should be.

If I have to, I'll construct something from plumbing parts. I'm almost certain water is getting in where that grommet should be. The firewall material folds under the metal cowl pan and rests against it. Without the rubber grommet/drain, the water flows out of the hole and between the firewall material and metal cowl pan.

Under my cowl was completely clean. I'm sure the previous owner and/or dealer tried to find the leak and thoroughly cleaned the cowl drains on the left and right side. All of that and the elephant nose drain were clean as a whistle.

The third and fourth picture here shows the drain grommet and the "tube" or water diverter that I'm missing. (sorry to post a link from a different forum)
http://z4-forum.com/forum/viewtopic....15283&start=45
The images above are from a RHD car where ours our LHD, so things may be a bit mirror-imaged.

I'll take pics when I pull my cowl again.

Salty

[StickMon]

I just have a big whoppin' hole in the underside right behind the jump terminal box.
Would have never known it was there.
No grommet or anything, just a hole.

I do have a big rubber plug in the firewall beneath it.
Can't tell from your pic since it would be behind that towel.
I tried to get a pic. The plug has the big "plus sign" ridges.

[SaltyNC]

Originally Posted by StickMon

I just have a big whoppin' hole in the underside right behind the jump terminal box.
Would have never known it was there.
No grommet or anything, just a hole.

I do have a big rubber plug in the firewall beneath it.
Can't tell from your pic since it would be behind that towel.
I tried to get a pic. The plug has the big "plus sign" ridges.

Attachment 1315489

You're a prince of a man, StickMon. Thank you so much for checking this on your car. That's very interesting that you have the same unplugged hole, as well. Now it makes me wonder if I've really found the leak, but I'm still hopeful that is it on my car. Maybe my cowl isn't sealing as well to the window in that area (I know it's not supposed to be watertight), and is letting more water into that area where it is getting behind the firewall/splashguard material. I can slip my finger between the hole and the material. Not sure if you could feel the firewall/splashguard material on your car when you were feeling around for the hole. Maybe all I need to do is get some silicon around the bottom of that hole and glue down the firewall material, so water can't run behind it.

You found the exact spot. Amazing since I had such a poor photograph. And I have that same large rubber plug in place.

Thanks again. This has been very helpful!

Salty

[kaybat]

just checked my 06 and i too have the hole,there's a rubber plug right below it that's against (what i believe is)the firewall.good luck.

[StickMon]

Originally Posted by SaltyNC

...

Thanks again. This has been very helpful!

Salty

That's why we're here

[SaltyNC]

Originally Posted by kaybat

just checked my 06 and i too have the hole,there's a rubber plug right below it that's against (what i believe is)the firewall.good luck.

Kaybat, thanks for checking on that. I guess that explains why I couldn't find a part on RealOEM.

I'm going to try gluing down the firewall/splashguard material on the underside of that hole. If that doesn't fix my leak, I guess I'll be taking out the seats, carpet, etc. again and testing with a water hose.

I appreciate you guys taking the time to check this!

[antennahead]

This is an earlier post that details my weird leak and the fix:

http://www.zpost.com/forums/showpost...1&postcount=13

[SaltyNC]

Originally Posted by antennahead

This is an earlier post that details my weird leak and the fix:

http://www.zpost.com/forums/showpost...1&postcount=13

Thanks! I had read your post earlier and checked for a leak there. I removed the door sill plate and plastic cap and checked for wetness, but everything was bone dry on my car in that area. Thanks again for the suggestion.

SaltyNC

[Varinn]

Originally Posted by SaltyNC

Thanks, bud. I had read that ordeal. In fact, I've read ever leak thread on the internet, I think. I believe mine is different. I think it really is missing a drain plug under the cowl. I wish I had taken a pic with the cowl off. I have the parts ordered, so I hope it will be the right parts. The illustrations on RealOEM aren't super clear for this area, but the elephant nose drain shown in the link in my original post is under the cowl, so I hope the other parts are correct and in this same area. I have the elephant nose drain in-tact. It's the small one that I think I'm missing.

I've already had my seat out and the carpet pulled drying it the first time. I thought the water may have been from the dealer being overly enthusiastic with a pressure washer when prepping the car, but it leaked after I washed it with a garden hose.

Thanks again for the link.

Salty

That thread is mine, so if you have any questions about the work I did feel free to message me. I tried to be comprehensive about posting updates and pictures but that's not really something I do often so it's pretty lacking.

To be completely honest I think that my leak was so unusual that it's not worth looking for something identical. If you were to take anything out of my post it would probably have to be that water has a way of travelling a long distance before coming down and into sight. Secondly it proves what I always heard that at least on modern BMW's, you have to be prepared to think outside the box on the inevitable water leaks. Don't just default to assuming it will be a visible or obvious gasket leak, etc.

[SaltyNC]

Originally Posted by Varinn

That thread is mine, so if you have any questions about the work I did feel free to message me. I tried to be comprehensive about posting updates and pictures but that's not really something I do often so it's pretty lacking.

To be completely honest I think that my leak was so unusual that it's not worth looking for something identical. If you were to take anything out of my post it would probably have to be that water has a way of travelling a long distance before coming down and into sight. Secondly it proves what I always heard that at least on modern BMW's, you have to be prepared to think outside the box on the inevitable water leaks. Don't just default to assuming it will be a visible or obvious gasket leak, etc.

I appreciate the offer and helpful tips, Varinn. I'm waiting for some parts to come in, and when they do, I'll pull my wiper arms and cowl and pull the seat and carpet and go back to leak finding mode. At least I'm learning a lot about how the car is put together.

All the best,
Salty

[Clearancediver]

The drain that you had the paper towel stuffed in has a little rubber flapper on it only. It drains the cowl area above and to the right of the drain to the hood hinge. I looked at mine and it was full of crap and actually had it blocked. Blew air backwards and used a vacuum to clean the area of the debris.

The firewall hole with a plug on it is likely where the sound generator tube that some models/engines use. Without the tube it would have a plug in its place.

Neither would cause a cabin leak....