Clogged Front Sunroof Drain

[m_thompson]

I had a wet passenger floor carpet after a rain storm and though of clogged sunroof drains. I pored water into the drivers side front drain and it quickly went down the drain onto the ground. On the passenger side the water stayed in the sunroof pocket. I tried snaking wire and weed-whacker string down the drain, but it would only go in about 6" and didn't clear the clog.

I didn't find anything specific to the E82 front sunroof drains, so started investigating. The front sunroof drains run down the A pillars. I pulled off the cover over the A pillar air bag and found that the A pillar is completely closed so there is no access to the drain tube. I pulled off the kick panel and also found that it was completely closed and that there was no access to the drain tube. I removed the six bolts that hold the front of the sill cover in place and pulled the front down. The sunroof drain is the rubber part that sticks out of the sill. One of the attached pictures shows what it looks like.

I tried to put a piece of weed-whacker string through the drain to unclog it, but found that the twine would only go in a few inches. I could feel something blocking the path, but couldn't see it. I grabbed it with some forceps, and yanked it out. It was a duckbill valve that is probably there to keep bugs from making a home in the drain. There is a picture of it attached. After removing the duckbill I was able to get about two feed of weed-whacker string into the drain and got soaked when I got through the clog. I poured a gallon of water down the drain to clean out any remaining clog.

I didn't replace the duckbill valve, and will now periodically flush the sunroof drains. I wonder how they assemble the drains when there is no access through the A pillar and the kick panel? I also removed the plastic panel that holds the carpet in place at the door opening, lifted the carpet, and found that the foam on the bottom of the carpet was wet. I put a large piece of wood under the carpet to hold it up and let it dry out.