Hi all.
I'm posting this as an informational item. It is something that I was fine with doing to my car, doesn't mean everyone else might be.
Please don't post anything about re-sale value of my car, every time you pass wind it lowers the value, its not an investment, its a car. Also please no questions such as why would you do something like this????? Or should have let dealer done it. Or should have gotten a set of new subframes and seals and fix it the way Porsche intended etc....

I hope this info helps someone decide what to do with their car and maybe give some ideas on how to deal with this issue if they come across it in the future.

Now to the root of the problem...
In every car, water gets in between the window and the outside seal, any and all cars do that. The doors need to be designed properly to channel that water back out. In the 997 the design appears to be extremely flawed. When the water gets in, it drips on to the subframe and should roll down to drain through the opening at the bottom of the door. The problem is that there is plenty of area at the bottom where the door and subframe meet, for the water to collect. And if the seals are dry or for some other reason do not seal just right, the water will start draining on to the inside of the door. Most know this as wet carpet at the bottom of the door. Mine was so bad you can squeeze the water out with your fingers.

This all can be fixed by purchasing the new subframe (seals are permanently affixed to the subframe) and spending two hours per door installing it. But if you keep this car for a long time and use it as i do (DD) it will happen again. So instead of wasting time and money on something that will be an issue again, i went a different route and did some "home engineering". I changed how the water flows. I essentially used plastic tarp to create something of a shower curtain effect. The water simply rolls down the plastic and out to the intended drains in the door and never make it to the seals.
Here are some pictures to explain what i did.

The first two images are not mine i got them elsewhere online to help you understand what and why i did it as i didn't take as many pics as i should have.

1. When you first remove the interior door panel, you will see a big black metal shield where several things are mounted. That's what i'm referring to as the door subframe. As you can see it is shaped to concave into the door.






2. When this panel is removed (carefully not to damage the window regulator and mechanism) you can see that there is allot of dirt and grime collected from the water sitting in the cavity. I found a good pic on PellicanParts to show this.




3. On the other side of the subframe you can see plenty of marks where water rolls down. I also marked in red were the seal is located at the very bottom of the subframe. Mine was so dried up and crumbling that i just removed it all. no sense in having garbage just hang around in your car





4. Here you can see an overall design which i think is just flawed.
The water rolls down the subframe and some of it ends up sitting inside the door until it dries up. I tried my best to create a visual but i havent touched Photoshop in over ten years, so forgive me. Also, no matter how tight the subframe is screwed on to the door, there is still few mm of room. Thus water doesn't just collect in the bigger valley on the left side of the closeup image, it has some room to collect all the way along the door.
So if the seals are bad anywhere along the bottom of the door, the water will end up leaking inside the car.










There are two openings all the way in the front and all the way at the back of the door that are lowest points were water could escape and would potentially serve as drains and not let water collect, but i think they may be getting covered up by rubber seals on the pins that hold the interior panel.
I could be wrong, water may not be collecting as bad as i think it may, but this is what i found so far so no flames please.








5. So, to fix all of this, I simply took some flexible plastic and created a "shower curtain". I taped it on the interior of the subframe that points inside of the door when reinstalled. Not the side you saw in the first image where it is facing outwards to you after the interior panel removal.





Created and sealed any openings needed for cables/wires/ window regulator and sealed it with very adhesive and water resistant aluminum tape. Stuck the bottom of the plastic on the other side of the door (inside the door) when reinstalling the subframe and water drains directly to the drain openings in the bottom of the door never even getting to the seals (in my case were seals used to be ).






The plastic is also on the opposite side of the window regulator mechanism (which is more towards the interior of the door) so it is absolutely not in the way of the window.






The car has been outside (flame suit on ) in several rain storms and thus far bone dry. Considering i no longer have any seals at the bottom of that assembly, id say it's working.


Hope it helps.
Happy driving.

 

Brilliant idea and one I will now copy as i have just noticed the bottom of my door cards are wet....

 

Excellent. I have the exact same problem on my 2006 C4S.

Yves

 

wonder if the 997.2 are any different? Very good job with pic s and all. Lots of effort !!
BUT now I feel justified for having a garage queen that's not driven in the rain, LOL

 

LOL, i never could have a car that i want and keep it in garage. i want to drive it all the time.
However, i found out that Cayenne GTS comes in 6spd and all of the sudden a bad weather car is not a bad idea

I would think 997.2 would be the same. the body is identical.

 

Thanks for the effort creating this valuable post - I'll be tackling this, but maybe not until the better weather
sometimes all it needs is a little thought such as this instead of spending a small fortune - Cheers!

 

Maybe a stupid question but why not just take a dremel and make the drainage holes flush with the bottom of the subframe so water cant sit down there?

 

Not a stupid question... Although I've never taken a door panel off to inspect the problem, logic dictates that a couple of strategically placed holes would indeed alleviate, if not, solve the problem.

Anyone else care to chime in on the pros/cons of this alternative?

 

hmmmm, sub'd here, haven't noticed this in my car, is this only cabs?