Sunroof question

[John Buchtenkirch]

Just wondering :confused: where the 4 drains on the sunroof on my 72 coupe actually drain ? Neither of the 2 coupes I did restoration work on so many years ago had sunroofs so I’m just wondering. Thank you ~ John Buchtenkirch

 

[Sven]

drain locations

John,

My '72 had the following:

The front hoses drain into the rockers at the base of the 'A' pillar. With the kick panels off you can feel the hose tucked into the rear inside corner.

The rear hoses drain out through the floor of the trunk just behind the wheels. You may see a couple of centimeters of the hose sticking out the bottom.

Here are some pics of the rear hoses modified (there is a second set that drains the 'C' pillar emblem into the rear section of the rocker - last photo).

http://www.larsenarchitect.com/BMW/Sections/Drains/BMW Drain Frameset.html

 

[John Buchtenkirch]

John,

My '72 had the following:

The front hoses drain into the rockers at the base of the 'A' pillar. With the kick panels off you can feel the hose tucked into the rear inside corner.

The rear hoses drain out through the floor of the trunk just behind the wheels. You may see a couple of centimeters of the hose sticking out the bottom.

Here are some pics of the rear hoses modified (there is a second set that drains the 'C' pillar emblem into the rear section of the rocker - last photo).

Thank you, what actually does the hole in the bottom half of the C pillar emblem do ? I had assumed it was something to do with the cars flow through ventilation system but that was just a best guess on my part. ~ John Buchtenkirch

 

[rsporsche]

Sven,

how are you going to isolate the dissimilar metals? you need to prevent galvanic action from causing corrosion between the 2 metals. its not a question of if ... its a question of when.

 

[Stevehose]

It's supposed to have a rubber tube attached to it which also drains into the rocker panel and is a great rust facilitator. I rerouted mine out the rear wheel wells.

Thank you, what actually does the hole in the bottom half of the C pillar emblem do ? I had assumed it was something to do with the cars flow through ventilation system but that was just a best guess on my part. ~ John Buchtenkirch

 

[Sven]

John - Nothing to do with ventilation. Its just to pick up the water that gets in through the recess behind/below the 'C' pillar.

Rs - You are correct, not to most ideal. I had tried to find a rubber elbow to avoid the copper to steel connection. The steel portion has epoxy primer on it and this should not see water all that often (ie, will not be continuously wet).

 

[John Buchtenkirch]

John - Nothing to do with ventilation. Its just to pick up the water that gets in through the recess behind/below the 'C' pillar.

Sven, I’m sorry, I’ve read your explanation several times but I still don’t follow :confused: your point. Is water getting in around the quarter side window and maybe there’s a tray underneath that picks up the water for that tube ? I don’t quite understand exactly where the water is getting into the car and why there is a hole in the lower half of the C pillar ? Thank you ~ John Buchtenkirch

 

[Sven]

There is essentially a flattened funnel behind the 'C' emblem to which the hose is attached. I have no idea why BMW thought it necessary to put this opening through to the inside. You can see the funnel shape in the photo. Check out the rear quarter panel section for more photos. The pressed in area in the rear quarter panel hangs over this funnel to collect water that comes through. It may also collect leakage from the rear window?

If you are not removing the rear quarter panel, then the easiest fix to as Steve suggested with the hose rerouted through the wheel well.