PFDGSB

So I got the wet passenger floor Friday. I had read about it so I knew what to do. Filter was wet so I replaced that, too.

​​​​​​I ripped the flap off the drain tube which hopefully prevents the same issue in the future.

But it's just weird. I LOVE my GTS, but I've never heard of a problem like this, or all of the other drain issues in these cars.

I've owned a lot of cars and trucks. I have a lot of friends. But I can recall zero times where I've heard of a car, outside of Porsche, that dumped water in the car due to a clogged drain.

Maybe I've been lucky . . .

Reeds

Happens to every make that offers cars with sunroofs, any drain can clog over time. A bigger contributing factor is where you or the people you know park their cars rather than this being a Porsche design flaw.

Infiniti:
BMW:
Mercedes:
Ford:

Gus B.

Looking to purchase a 2011 CTT and the current owner complained to the service desk that the car smelled of humidity. During the last service, multiple sunroof drains had to be cleared.
I'm also waiting for a Mercedes Benz G500 to be done with some interior work that was due to a clogged sunroof drain that caused the cable that opens and closes the roof to fail as well as affecting the headliner (required replacing).

As Reeds mentioned above, it's a very common issue that many fail to look at and can create havoc in many different brands.

PFDGSB

Wow - I never knew this was so prevalent.

KBell

Occurred in my old Honda (20 plus years ago)
My brothers VW golf (recently)

ANY car with a sunroof, better check then drains.

Sudar

Parked my Lexus and Nissan outside for a long time, never had any issues in over 120k miles

Gus B.

Some vendors have better ideas/mechanism than others regarding drains. At the end of the day it's a "careful balance" between allowing liquids to easily drain from the roof to the bottom of the vehicle while at the same time prevent liquids from the bottom of the vehicle to enter the vehicle. A "simple" one way valve would be the obvious choice, but taking into account what could potentially come down the drain tube (depends on diameter which in turn affects capacity/volume to extract) and the pressure with which it comes and then how materials lose flexibility over time, you can then see it's not such a "simple" answer.

The "simple answer" is to make sure that checking the drain tubes with each regular/yearly maintenance is performed. This applies to any vehicle brand, not just Porsche.

957 series Cayennes are notorious for severe expensive damage due to clogged drains because the ECUs can be easily damaged....

Whitegalaxie

Any car that has blocked drains has not been serviced at the dealer or a reputable indie as thy know the drains must be cleared yearly. I would stay away from a car with any signs of dampness or musty smelling. A sure sign corners has been cut in the maintenance.

leftlane

My Cayenne is the only car I’ve ever had this issue with - ever. Add that the electronics including the battery are under the seats and it’s not a good combo.

idigsnowboarding

The drain issues have been annoying on my CS. I just dealt with the wet front passenger floor issue a 2nd time and came across a TSB about the AC condenser drain tube (different than the sunroof drains). Pull the plug, complete the cut, painstakingly jam the plug back thru the firewall, and hopefully it’ll be fine.

https://static.nhtsa.gov/odi/tsbs/20...43835-9999.pdf

PFDGSB

This is exactly what I did. It worked, but getting that drain back in the firewall was tough with all the insulation in the way. I got it though.

DrBillyD

Have dealt with clogged A/C condensate drain more than once on my 958.1. Finally cut the flapper at the end and no problems since, though I do blow out the line when I change the cabin air filter.

First time I tried getting tube back in place in firewall was a PITA as described above. Second time I used a little plumber's grease on the part of the tube that seats in the firewall hole and installation was much easier.

BrendonSF

For what it's worth, you can also just buy a new drain tube for $10 online or at the dealer. At 110k it feels like the right call since there's probably a fair amount of build up inside.