BMW Z4 E89 3.Oi 2011 - Water Ingress but no leaks

[Stash36]

There's loads of threads on this very common problem.

Check rear light seals seated correctly. If the tool cubby hole is wet that is probably your left light seal.
Check air vents to left and right have been replaced.
After that it's trial and error, can be the third brake light or the main boot seals, which are very expensive.

Must admit I have solved this problem in the past but found boot flooded recently. I think it is something not fully understood such as water coming out of the roof when stored, or perhaps pressure washing.
The story the OP recites about BMW spending hours on it without a satisfactory answer is telling.

 

[warmasice]

Dear All

Hi - I'm new to the forum and sad to say starting with a problem...

We've just taken delivery of a 35is after about 4.5 years running a 2.0is.

Anyhow, I was shocked to find quite a lot of water in the battery well and in a pool in that conical tubular hole in the foam to the right of the roof pump. I must have removed nearly half a litre so far. The water is clean and tasteless and possibly had some detergent in it as I noted slight foaming when wringing out the kitchen paper I've been using to mop it up.

It been raining really hard since the car arrived so I don't know if it is rain water getting through somewhere, or possibly its from being pressure cleaned by the garage we bought it from.

I have checked the carpets on both sides inside the cabin and both are perfectly dry. So I think the cabin is water-tight at least.

Looking in the battery well, there is no water staining or corrosion that I can see - so if I had to guess, I'd say it was recent water, rather than water that had been there for a long time.

I guess my first question is should I simply start by trying to remove all the water and checking it each day or do I need to go straight to a garage to have something replaced / cleaned - maybe a rubber seal, drain hole or vent (I've had a brief read of this thread)?

Kind Regards to All

Change both rear light seals and bot vents. I'd start there.

 

[mcbutler]

I would be inclined to place an action camera or similar inside the boot with a light and run a hose for 20min turning the camera every 20min to cover the whole boot.
Or maybe a non permanent dye that will leave a trace inside the boot for you to follow
Or - dont judge me - do you have any small children/grandchildren lol

 

[dakargelb]

Thanks guys.

Regarding the light seals and vents, does anyone have the part numbers / a recommended supplier for these or do I need to head straight to the dealer?

I'm still getting water out - there's far more than I imagined.... <sigh >

(Oh, and the car is Black Sapphire, with red seats / aluminium trim.)

 

[Pondy]

Thanks guys.

Regarding the light seals and vents, does anyone have the part numbers / a recommended supplier for these or do I need to head straight to the dealer?

I'm still getting water out - there's far more than I imagined.... <sigh >

(Oh, and the car is Black Sapphire, with red seats / aluminium trim.)

To be honest, if I were you I would dry it out thoroughly and see what happens before changing expensive parts which may not be the problem. As you eluded to in your first post, it could have been 'put there' recently by someone pressure washing it from underneath.

There are many useful threads on here about water in the boot of E89s. I would do a search and familiarise yourself with the likely problem before doing anything else.

 

[flybobbie]

Dry it out and then ring the boot with some kitchen tissue to see from which direction it's coming from.
Also check under either corner under the trim, that might be full and flowing over.
Few have had problems where the boot rubber trim runs across the back. Two rubber trim end bits with hex screws.

 

[clarker63]

Change both rear light seals and bot vents. I'd start there.

yup, the most likely cause of this, and the top boot seal also mentioned - see this thread..

https://z4-forum.com/forum/viewtopic.php?t=115469&hilit=leak

 

[warmasice]

Thanks guys.

Regarding the light seals and vents, does anyone have the part numbers / a recommended supplier for these or do I need to head straight to the dealer?

I'm still getting water out - there's far more than I imagined.... <sigh >

(Oh, and the car is Black Sapphire, with red seats / aluminium trim.)

Get them from the dealer. Save yourself the time and headache. Change the seals and vents, they don't cost that much. Start there first.. see how you get on, then look at your boot seals after. Been there, done it!

 

[dakargelb]

Thanks for the continuing advice it is greatly appreciated. Still drying it out before I replace those seals or indeed try to trace how it's got in. I'm shocked by how much water I've removed - I'm guessing it was soaked up into the foam around the pump...

 

[warmasice]

Once you replace the vents and seals, you may still find water finds its way into the boot. It's actually the water in the chassis rails. Hard braking and sharp turns should get it all out over the course of a few days. You'll also want some of those pound shop moisture absorbing packs.. I put around 6 in to soak up any lingering moisture. Worked a treat and boot has been bone dry. I've posted a few thread/posts like a lot of others. Lots of useful advice on the forum.

 

[dakargelb]

I'm still drying the battery well out, this weather isn't helping though...

I've got some of those bags of silica gel in there too to help take any moisture out of the air.

I may have had a hint as to where the water is getting in: I noticed some drips coming in over the curved metal at the top of the battery well on the left hand side as you look at it.

I had to fiddle with a rear brake bulb which hadn't been seated correctly and I was surprised that there really isn't much between the inside of the boot and the elements, save for that rubber seal that you guys have all kindly mentioned.

My current guess is still that the selling garage had jet washed the shut lines / gaps around the rear lights.

On a positive note, I've driven the car a few times now and that engine is amazing!

 

[clarker63]

I may have had a hint as to where the water is getting in: I noticed some drips coming in over the curved metal at the top of the battery well on the left hand side as you look at it.

that was my issue. water was getting into the space below the small opening hatch/storage area on the left hand side of the boot (either from above from the top seal, or through the lights). Once the water is there, is can go into the chassis rail and then "spew" out when moving, despite no obvious water getting in anywhere else. took me a while for this to go (see my linked thread above). I left the boot trim out for quite some time to ensure no water was anywhere in there. it hides under all the trims/pump foam/etc so its not easy to track down otherwise.

 

[Busaboyjd]

Less than 2 months of ownership and this.

F*#@!!!

 

[RobbiZ4]

Oh s**t!

At first take the hydraulic pump out of the water. Remove the two foams and get it replaced by new parts. Open the 2 screws of the pump's e-motor on the right and remove the silver cover. Not the motor itself, only the metal cover to get the water out of the motor and let it dry carefully.
Check the red fuse box on the right with a multimeter: each pin on top should be on +12V. If any pin fails, the complete box has to be replaced as well.

If the motor has dried, check if it has a short or works correctly. Don't connect it to the (renewed) fuse box before you are sure there is no short on the motor.

 

[RobbiZ4]

Has the vehicle been repainted at the rear, wrapped in foil or have the taillights been renewed?

Then one or both tail light clusters got mounted wrongly.

 

[Busaboyjd]

@RobbiZ4, Thank you so much for the reply. I removed the battery Monday afternoon, it was completely dead. I dried the trunk with a shop vac and left it sitting in the sun Monday evening, Tuesday, and today until 4:00 PM. The trunk looked completely dry, and the battery took a full charge, so I reconnected and drove the car. Everything seems to function except the top.

On your advice, I removed the motor cover, which was full of water; thank you for that tip! The relays, along with all of the 12v connectors on the red junction/fuse box, are covered with corrosion. I have not tested the red fuse box for power, it has been years since I worked on things, and I no longer own a multimeter.

I am not certain this was not a known issue with this car, which is why the dealer failed to supply me with the 78 service records they boasted of. The car was a single owner with a clean vehicle history report, and I don't see any evidence of paint work.

I am wondering if there are stopped-up drain tubes that are designed to allow water that escapes the top seal of the fender to drain out. And that is how I got so much water in the trunk. It rained hard for three days and I had just had new wheels and tires installed Friday; today's test drive had a few curves to check the new tires, and more water appeared in the battery compartment.

Thank you for the engagement and for probably saving me the cost of the motor! I will keep you and the thread updated on my progress and maybe my frustrations

 

[Smartbear]

I wouldn’t refit those salmon relays, it can be curtains for the roof motor if they fail in use.
Rob

 

[RobbiZ4]

I wouldn’t refit those salmon relays, it can be curtains for the roof motor if they fail in use.
Rob

Correct!
Please renew:

• 2 salmon relays (12631742690)

• 1 red power distribution box (61149192124)

• pump's foam (51479139043) and cover (51477225246)

Part numbers can be found here...
https://www.realoem.com/bmw/en/showparts?id=LM51-EUR-01-2010-E89-BMW-Z4_30i&diagId=54_0402
... and here:
https://www.realoem.com/bmw/en/showparts?id=LM51-EUR-01-2010-E89-BMW-Z4_30i&diagId=61_1860

You will find additional water in the following days after your next test drive. Currently it sits in the long frame rails from the back to the front of the car and will drop out slowly. Get all plastic covers removed out of the trunk (use a nail iron for all the black pins) , as water will be in the outer spaces below the ECU's on the right and the little box on the left. Place tissues everywhere to catch each drop.

Nail iron:


Use an anti corrosion spray for all the big plugs of the red fuse box and try to clean each with a small brass(!) brush. Same procedure with the 2 relay sockets as well as the pump's motor.
Dry all parts with air pressure and tissues. You will get all these tools and spray cans in a hardware store next to you (hopefully).

 

[RobbiZ4]

This massive corrosion is the result of months of water in the trunk, not only from the last three days.

I'm pretty sure, that neither the first owner nor the dealer knew this issue and had a look into this area of the trunk, if the roof still worked until you bought the car about 2 months ago.

 

[Chippie]

Check the rubber seal along the top or the boot/trunk (below the rear window/screen) as that’s possible where the water is getting in, the jointing/sealing compound with have broken down, mine had.