Wayne Smith

My 2010 C4S sat in much needed Northern California rain at work today. As I drove home in the dark I had an occasional drop hitting me. At home in the garage I found a wet roof liner near the drivers window toward the windshield, picture attached. The water is above the windshield, so I don't think that is the leak. There was no wind to speak of. It is also a long way from the sunroof. There was a bit of water inside the sunroof, but very little. I popped the cover on the roof carrier mount and found the screw loose, but pulling that screw all the way out exposes a blind hole, so I don't think that is at fault, although that seems to be the area of the leak. Am I missing a drain hose as I look at this (that might be plugged)? I don't see anything on the car or in the parts book, although Illustration 801-45 indicates that the plate the above mentioned screw goes into could be a potential leak point.

Any ideas?

mattyf

Not sure if this is helpful because I've never had this problem, but in the 997.1 catalog there are sunroof drains:
http://www.porsche.com/all/media/pdf...97_KATALOG.pdf

You can see them in the catalog if you search for sunroof. I haven't gone downstairs to see if I could find them in my car.

Wayne Smith

Found it in illustration 811-00. Thanks. Will look to see if I can find it on the car and blow it clean in the morning. Will let you know the outcome.

Wayne Smith

Flashlight required to see the hole for the front hose. Not sure about the rear hose. No debris, but that doesn't mean the hose isn't plugged or leaking. Will need to check it this weekend.

Corrections to last night ... Location could be windshield involved, and if leaking from the sunroof the water could have run downhill to the corner before seeping through.

The liner was dry this morning and with heavy rain at the office today there is no sign of leakage now. Maybe opening and closing the sunroof "fixed" it.

I hate intermittent problems!

semicycler

The second and third pictures are the roof rack mounts. There is no opening to the inside of the car under that. The entire track can pop out to verify. See illustration 810-00 on page 297 in that same pdf posted above. Sunroof drains are the most likely culprit.

If you reach the point where you want to remove the headliner to visually inspect the drains, see this thread: https://rennlist.com/forums/997-foru...of-rattle.html

Wayne Smith

Thanks. I don't trust this to not return, so some investigation is in order for the weekend!

BrakingBad

Keep this thread in mind if you need to replace anything.

https://rennlist.com/forums/parts-ma...-interior.html

Wayne Smith

Thanks. I certainly hope it doesn't come to this! I'll need to lock up the gremlins before I start pulling on glued together plastic pieces.

Edgy01

The real issue for you to answer is simply--do you ever park in a way that tree leaves can fall on your car? If so, there is the chance that a critical drain is plugged. These cars must have their drains checked routinely as a part of regular maintenance. Otherwise--you don't want to know the extent of the damage that can ensue. In the 996 forum I recall reading about a guy whose drain plugs up front caused his engine to fail.

Wayne Smith

I was suspicious of debris letting water in past the gasket. But as you point out, the drain should act as a secondary safety. It required a flashlight but I did locate the front drain hole ... It was completely clean. I did clean around the sunroof opening, although the was no evident dirt to be had. That does not preclude a leaky hose from letting the water out prematurely, and into the headliner! The hole still would allow about 1/32" of standing water. I had a mist of moisture only under the gasket. Not anywhere near enough to get to the drain hole. So I am not focused on the drain right now. I figure that I either have a crack in the sunroof tub letting water through (doubtful), or I think the leak was from the windshield. Unfortunately, it self healed. This weekend is slated for a few hours to attempt duplication. I will let you know what I find.

These cars seem to be great mechanically, not so much electronically. The idea of a water leak halting the motor irks me. Have the Germans never heard of silicone seal? Before anybody takes offense, I'm half German. We water proofed a lot of desert bikes and trucks for monsoon season and mud runs. It isn't that tough. Has anybody tried this on a 911? Or is what I've been reading on this Forum making me paranoid?

Edgy01

The issue on the 996 forum that I read of some time back was hydrolocking. Somehow the water damming up inside the front area (battery area) got into some vacuum line that ultimately led to the death of the engine. Granted, it was one incredible comedy of errors, to see something as simple as leaves in the front area of the car leading to an engine failure.

Wayne Smith

I miss the dipstick. 4000 miles between oil changes is a long time to wait to see if the oil is contaminated with water or antifreeze. Some comedy of errors!

misterdega

I know this is an old thread but OP, did you ever find the solution?

sp1ke

This post may be of interest, it details a similar leak from the roof bar mounting point on another 997:

http://911uk.com/viewtopic.php?p=1582538

groovzilla

Make sure the sunroof drains are clear. Requires long wire. In my 996 I used A base guitar string to clean the drains
Not easy when they get really clogged up.

https://www.google.com/search?q=pors...0PEPt8O--AM_29