Water leak

[Varinn]

It's pretty shit, I always heard rumors that modern BMW were prone to leaks and broken plastic bits. I didn't believe it before but do now! My buddy helping me with this has an e90 M3 and besides the vague steering, effortless clutch, overpowered brakes, and the creaks and groans on the interior... His steering adjust lock lever just snapped off when he unlocked it to move the wheel!

When I get this sorted I'll be happy, between the Z4M and the M3, I would without hesitation take the Z. So much fun to drive! The M3 however, I didn't care for.

EDIT: Driver seat and general module are back in the car, I'm going to drive it down to my friend's shop after work tomorrow and see if I can borrow the smoke tester from the glass shop next door to them. Maybe it will work or at very least a fresh set of eyes and some new techniques for sourcing the leak... Took it out for a spin to see if it would work as is, so loud inside with no carpets/trim etc. Definitely harder to shift with no material under the clutch pedal.

[Varinn]

Success! (I think)


Took the car to my buddies shop and the glass guys next door helped me out for a couple hours to track it down. Ended up finding it by using some foaming spray they use that breaks down slowly. With that and an airgun using a long flexible hose attachment we were able to feed it up inside the cavity and push air out backwards, it took about 45 minutes but we saw a single little spit of air come out on the cowl seam. Followed that up with a hose and isolating small sections at a time using butyl strips and waterproof tape to direct the water flow where we wanted, we found a few small holes in the factory sealant between the plates. I've got no idea how we ended up so far off in our original search area, I guess when we thought we were directing the water well away from the cowl it was still finding a way to run down the lip to the hole, pass through, then work its way back across again to the corner and come down behind the speaker.

This picture shows the general area, strangely the two most "visible holes" in the sealant (one to the left of the clip hole, and one further towards the corner) were not the sources. That would have been far too simple. It was actually on the RIGHT side of the cliphole in this picture, but not visible here. This photo is taken with the voids already filled with the clear glass silicone (You can see the result of the stuff easily at the left side, it looks like water)


Let it dry overnight, tested it at my friend's shop again with no leaks. Drove the car home, tested AGAIN with no leaks. So I half-assedly painted seam sealer over the top of the worst areas as an added protection and re-installed the cowl. I'll test it once again today by washing the car, if no water finds it's way in then I will call it fixed and put the interior back together. I might go back one day and paint the sealer with touch up paint to try and somewhat match it to the silver on the car, though it's almost completely hidden by the cowl anyways.

[inTgr8r]

Great news.
You have done a terrific job with this.
I'm sure this will be invaluable info for others in future.

[Vanne]

bloody hell mate, great investigative stuff here, you working for CSI by any chance? seriously though mate, good stuff.

[Finnegan]

Originally Posted by inTgr8r

Great news.
You have done a terrific job with this.
I'm sure this will be invaluable info for others in future.

Absolutely. doesn't even start to cut it.

Originally Posted by Vanne

bloody hell mate, great investigative stuff here, you working for CSI by any chance? seriously though mate, good stuff.

CLI (Car Leak Investigation). Quite a tale of persistence and patience. Darn impressive!

[elerner61]

I hate water leaks. Had a leaking glass hatch on a 944 (which they eventually all do) that I could never resolve.

One question, with the plastic cowl in place how does water make it to the section that had the hole(s)? Isn't that under the cowl?

[Varinn]

Originally Posted by elerner61

I hate water leaks. Had a leaking glass hatch on a 944 (which they eventually all do) that I could never resolve.

One question, with the plastic cowl in place how does water make it to the section that had the hole(s)? Isn't that under the cowl?

Magic.


But really, water is a bitch, it finds a way. As far as we can tell it was traveling down the seam to find its way in during driveway testing without the cowl. The plastic cowl cover isn't a waterproof seal on the glass however. It's mainly for cosmetics and I guess for directing MOST of the water flow through the designated channels, leaving just the leftover traces that make it through to use the other drain.


Did some installing after work last night. Washed the car and found it stayed dry inside so I started putting things back. Picture here was right after I got the carpets in, the kick panels and rear speaker/side trim pieces are all installed now but it was too dark for any photos (was working from a flashlight)

[Incompatible]

Another thanks for posting. Great step by step commentary and photos. Sorry you had to go through this.

[Varinn]

DOH!

Made one small mistake, my hand slipped when I was pulling on the carpet and I accidentally bumped one of my "subwoofers" with my elbow, denting the dome.

My knee jerk reaction was to immediately look up the difference between oem replacement and an aftermarket. I believe I have the "Carver" system, which as far as I understand it makes them much harder to replace? I never did care for the bass in the car, it ends up sounding very muddy and flat.
S645A BMW US Radio
S677A HiFi System Professional DSP


Beyond that though, cold or no cold I'll hopefully get the car completely re-assembled this afternoon when I'm off work.

[HarryFD]

Hi, I am having water intrusion into my 2003 Z4 on the passenger side. I think you may be on to something but since the changes in Photobucket, your pictures are no longer loading.

Could you repost please?

Thanks!

[SaltyNC]

Originally Posted by HarryFD

Hi, I am having water intrusion into my 2003 Z4 on the passenger side. I think you may be on to something but since the changes in Photobucket, your pictures are no longer loading.

Could you repost please?

Thanks!

See attached. When I first got my roadster, I had a leak that turned out to be completely different from this, but I saved this thread while I was doing research.

Salty

[SaltyNC]

Second half...

[HarryFD]

Originally Posted by SaltyNC

See attached. When I first got my roadster, I had a leak that turned out to be completely different from this, but I saved this thread while I was doing research.

Salty

Thanks. I did a brief disassembly today (entry sill and speaker cover. Pulled back the carpet a bit and sprayed some water on the passenger side. NADA! Need to spend some quality time in the next few days.

As it is my commuter car, I really do not want to do major disassembly of the interior, if I can avoid it.

I was thinking it could be a clogged AC Condensate drain. Does anyone know where it discharges?

[StickMon]

It drains above the trans, and rusts your trans mounts.
I put an extension hose on mine so it drains below the mounts.

Edit: Found the thread on the AC drain and its deleterious effect on UUC trans mounts.
My drain extension is on page 2.

[SaltyNC]

Originally Posted by StickMon

It drains above the trans, and rusts your trans mounts.
I put an extension hose on mine so it drains below the mounts.

Added to to-do list. Thanks, StickMon!

Salty

[HarryFD]

Thanks for the info. I am investigating.

[dc_wright]

Something else to check is the cabin air box drain. Stumbled onto this while replacing the fender liners. The exit is behind the passenger side fender well liner. Mine was absolutely packed solid with leaves and other crap. Hard to see where it was allowing anything to drain through it. Pics are after I cleaned out about a pound of crap. Possibly you're getting water backing up through the ducts and exiting into the passenger foot well area?

[HarryFD]

Originally Posted by antennahead

This is how my roadster was leaking. Water was running between the fender and the door at the base of the A pillar. It was hitting the plastic piece that you have circled in blue. That piece was diverting the water to the small channel that runs down the gasket seal (see my new blue line showing the water direction). The water runs down the seal until it gets to the door sill area parallel to the ground. From there it was flowing into the floorboard as a steady trickle (see my blue line), depending on how hard it was raining. I came to the realization that "maybe" the round hole in the gasket, circled in red, was supposed to allow the water to run out under the gasket. If that was their engineering genius, the hole was way too small. I took an X-acto knife and turned the small circle into a rectangle, about 3/4" long by 3/8" wide............ problem solved, no more water running into the floorboard (I added the rectangle in red, for reference, below the existing circle in the photo...... the new rectangle I cut however was in the exact spot as the circle, I just enlarged it). This leak drove me crazy, and the only way I solved it was by being stuck in rush hour traffic at a standstill during a torrential downpour. I began studying the problem, went home and later recreated it with a water hose. It's hard to believe the enlarged circle to a rectangle stopped it, but it did.

BINGO!!!

I have been fighting the same thing and this post is exactly the answer. Two small holes added to the door weather strip (1 on each side) and the water stays out!

The location is approximately as shown. I looked at the small puddle that formed on the weather strip and added a hole to the leading side.

Thanks for the tip!

[antennahead]

^ I'm glad this worked for you. That leak drove me crazy as well, and for once being stuck in rush hour traffic in a downpour had a positive outcome Sorry I didn't locate my old post and re-post it in this thread to help you earlier, it's been a trying few years for me with two parents I had to be primary caregiver for. Glad your problem is solved

[HarryFD]

Originally Posted by antennahead

^ I'm glad this worked for you. That leak drove me crazy as well, and for once being stuck in rush hour traffic in a downpour had a positive outcome Sorry I didn't locate my old post and re-post it in this thread to help you earlier, it's been a trying few years for me with two parents I had to be primary caregiver for. Glad your problem is solved

No problems. Part of what makes forums like this great is that if one person can't help someone else will (Thanks SaltyNC). We are all in this together.

Hopefully at some point I will be able to contribute something as well.

I was helping my brother with my parents with the same thing until they passed (aged 95 and 99) a few years back. I appreciate your priorities.


Take care and happy holidays.

[Varinn]

Glad to see this thread is proving helpful for people still, sadly I no longer have copies of any of the photos I had posted here and I don't even own my Z4 anymore to take new ones.

The new owner is a great guy and I've met up with him a few times since so maybe next time he's around with the coupe I can snap some new ones to better explain. I don't check in here much anymore, for obvious reasons.