OK it happened to me. 2010 E61 11/09 build- original owner. I have been aware of this problem since day one and have had the dealer blow out the sunroof drains every year.

Still got water in the sparetire well.

Last month got a TPM malfunction light. Took it to dealer and they discovered 1/2 inch of water which had fried the RDC module. Here's the odd part: They tested the drains and they worked perfectly. They noted calcification on the hatch seal and their theory is that the hatch seal went bad, so they are ordering me another hatch seal. Even though this is their theory, they were unable to replicate the problem.

So, anyone else seen this or care to comment on their theory? BTW, I'm not out to get the dealer- I have a good relationship with them and they replaced the RDC module and the hatch seal under warranty.

 

Very odd... The 2010 drains in the rear have a different design too, without the end plugs, so they shouldn't get clogged up either.

 

By hatch do you mean the trunk seal? My '06 drains were clean and fully functional when I discovered about one inch of standing water everywhere in the trunk area. It turned about to be failed sunroof seals. They are spongy in their proper state to tightly seal and mine had become dry and compacted, allowing water to seep in during rain and drip in from car washes. The replacement was very easy and inexpensive.


In my experience, the dealers refuse to acknowledge this problem. Calcification? Seems unlikely unless your car is washed with hard water daily and the seal does not dry quickly. Rainwater is usually soft.

Apparently it is also a problem with X5s (same unit), so they have a moderately defective unit making the rounds across a few models.

 

Good thought, I'll check out the sunroof seals

 

I was proactive and removed the SureClog valves at the end of the drain lines in my 2007. I too thought I was safe. Then I went through a snow storm and did some off-roading in bumper deep snow (unintentionally). Shortly thereafter, I suffered failed electronic modules due to water in the spare wheel well. The dealer diagnosis said it was a failed rear vent (just above the battery). If you look at that part, it doesn't make sense. I've taped a bunch of paper towel strips around the spare tire well and various paths to the spare tire to trace any new leakages. It's been about 2.5 years since and there have been no leaks since. IMO, I think it's the junction where the rear bumper transitions to the trunk. I guess I agree with the trunk seal theory then. Or, it could be even the taillight lens gaskets.


TwoPedal, if it's a failed sunroof seal, doesn't the leak still go to the drain pipes? If not, where?

 

Yeewiz- sorry for the long wait.

I am by no means an expert on the topic, but the way it was explained to me is that the failed seal allowed water to fill the track. With the track full of water and the drains pipes clogged, the water just leaks down the path of least resistance, which in our case seems to be down the rear pillars and onto all the electronics.

I found on the most intrusion on the battery side. The padded fabric that normally covers the fuse panel was soaked and the fuses were wet. Fortunately, it did not cause any permanent damage but while it was wet, the blinking alarm light under the rear view mirror stayed on constantly for about two days.

I am not sure if this is an official procedure, but my dealership raised the electronics in the spare wheel compartment a few inches to keep them out of the way if it happens again.

A failed rear vent sound suspicious. Its purpose is to vent hydrogen generated when the battery charges. If your car was bumper high in liquid water it might happen, but snow sounds like a stretch. I am not even sure how a vent like that fails- maybe the seal.

 

The sunroof seal is meant to be porous. Sounds like your problem was the clogged tubes.

 

Had major water damage from sunroof leaks into headliner and down rear roof column...and over $7000 damage to ECMs...dealer refused to cover (car 3000 miles out of warranty and took position that damage caused by "environmental" factors)...tried to say it was my responsibility to clean panoramic sunroof tray just as it was my responsibility to keep leaves out of the space between hood and windshield!...I asked them to show me the section in the owner's manual regarding my responsibilities for the environmental care of my car...I also asked them to show me the disclaimer that I shouldn't/couldn't park my car outside under trees...problem had showed up once I started parking outside at work...after three service visits where they were unable to replicate the leak, I actually experienced leak on way home from dealership after third appointment during a heavy rainstorm...turns out the tray that collects the water and delivers it to the drain tubes was cracked...they replaced it and problem went away...FYI...I contacted regional service engineer and after pleading my case and referencing multiple forums discussing design flaws of the panoramic sunroof and the undersized drainage system, BMW paid the dealer for the repairs...haven't had problem since...so check the tray for hairline cracks...

 

Wow, well done!

I'd say the cleaning of leaves between hood and windshield is your responsibility though...

 

Great advice, thanks- do you have a part number or picture of the offending tray?