C-Pillar Drains

[Markos]

Moving this discussion out of FS section to avoid a thread hijack.

At this position the BMW emblem covers a venting hole with a drainage pipe. If the pipe got clogged or loose water will assemble at this area. And with the CSL's thin metal body it did not take long until the damage was done

@TomHom,

I didn’t really understand these drains until I removed my rear fenders. I took some pics of the removal process but put together this image based on someone else’s well-captured photo. Reason being is that many people think the sunroof drains into the rear rocker, which is incorrect. As you have seen with your CSL, all e9’s have the C-pillar drain.

 

[Markos]

The thing about this drain is that there is no significant way for debris to enter. The only way it could clog is if an insect crawled in, or something like pollen clogged it after 20 years.

Water enters this area from the rubber seals on the glass. That lip that leads to the gutter isn’t to be confused with the boot gutter that retains the rubber seal. That lies outside of this channel.

Here is another pic from @xjan99

 

[TomHom]

I understand this opening as the outlet of the forced ventilation. Air being blown into the passenger compartment will exit at these point. The air condensates on the steel parts, the condensate water will be drained by this pipe and the hose. But you are right, clogging at this point is unlikely

 

[Markos]

I understand this opening as the outlet of the forced ventilation. Air being blown into the passenger compartment will exit at these point. The air condensates on the steel parts, the condensate water will be drained by this pipe and the hose. But you are right, clogging at this point is unlikely

I would argue that you don’t need an opening for “forced ventilation”. I can hold a solo cup outside my car window at cruising speed and I don’t need a hole in the back.

You do need ventilation for drains however.