commok

2015 Carrera GTS Cab PDK - bought CPO in 2016 - never wrecked or molested... Over the last couple of years, when using a/c during summer months, I have noticed water dripping from the seam between the front underbody shield (pn 991.504.601.08) and the center underbody shield (pn 991.504.603.00). I asked the dealer last year when being serviced - "why is water dripping from the seams between the center shield and the front shield - maybe a clogged a/c drain?" and they claimed it was supposed to be that way - no issues... So today, while completing my DIY oil change, I decided to take the shields off and see why water is pooling and dripping out between the shields. Here is the underbody - dripping water a/c drain drain circled in red to the right... It clearly was dripping water, so I found the a/c drain... but I noted the hose end in the tunnel - - what is the hose in the tunnel? The tunnel hose is dry, so not a/c drain - so battery vent? Anyway, back to the a/c drain...



The a/c drain is dumping water unto the underbody center shield, and since there is no direct path out, the condensate is pooling around until it either sloshes out, or evaporates... Here is the shield - drain location to the front right (red circle) - pooling in the center (blue circle)...



Red circle is directly under drain, blue circle is the pooling residue...

So the question - is this as Porsche intended? Pretty cheesy, if so, and not good for the fittings underneath to have no drain, and clearly leading to corrosion.. I am thinking about breaking out the hole saw and cutting a port directly underneath the drain... thoughts?

bkrantz

Nice detective work. I agree with adding a drain hole in the under-tray. But you might increase the body coefficient of drag by 0.00002%

Carl Over

While you are driving the drippings will not likely go through a small hole. Maybe a hole in the shield and hose extension to protrude through the hole by 1" Ala gas flap drain hose.

Tier1Terrier

I'm guessing that the hose in the tunnel may be a firewall/body drain. Strange though how there is not a direct drainage path for the AC down to the ground. This topic intrigues me so I am going to follow this closely. Too many stories about water damage out there due to insufficient or clogged drainage.

commok

I am wondering if my 911’s configuration is different from others - do all 911.1’s drain a/c condensate in the same manner?

commok

Broke out the hole saw, put a 1-1/2” hole underneath the drain, and additionally drilled three weep holes in the area where the condensate had pooled… I might put a small hose to help the factory drain in the future, but for now, trying this approach… a couple of the nut clips were corroded, so replaced them, and sprayed CRC over all the ferrous fasteners underneath… still questioning whether Porsche intended this to be the norm…