sunroof drainage leaking

Hi All I've searched around on here & YouTube, but not found anyone else that has quite the same issue. The common causes seem to be blocked drainage tubes which doesn't seem to be the case here. So I was wondering if anyone here has come across this, or if anyone has any suggestions on the best way to fix this. I found a couple of damp spots on the headlining in both rear corners which seem to occur after a wash or when it rains. I peeled back the edge of the headlining & to investigate & it looks like both sides are leaking where the plastic bit coupling point for the drainage tubes joins to sunroof mechanism. It looks like it may be possible to remove this from the sunroof mechanism. So it might be possible to apply some glue or sealant here, but I'm wary that this could obstruct flow to the tubes & cause a different issue. Any suggestions on how best to address this gratefully received & a bonus question - I understand the drainage tubes exit behind the rear wheels. I couldn't see anything behind the wheel arch liner above the sill. Is it the bung shown in the 3rd pic below which is in the section above the rear bumper? cheers

I'm afraid i know more about Targa roofs than these but the drain would seem to be similar .. look over the top of the bumper support , over the silencer and theres a tube there .. on Targas thats one of the drains so i assume its the same for you . I imagine its a case of removing the entire frame then removing the rear drain to reseal it ... For me i would just dry it and use silicone sealant around the outside .

Thanks Ian FYI I found the plastic connectors can be removed from the drainage channels by gently levering the clip on the outer edge down. Once removed, You'll see there is a groove around the edge of the connector which is filled with the remains of some black sealant. Possibly the 3m stuff shown in the rennlist guide for replacing the external seal around the edge of the sunroof. I cleaned these up & replaced with some fresh sealant which should hopefully resolve the leak for another 10 plus years. If not it's a fairly easy job to remove them again to renew the sealant.

Just had a sustained heavy downpour here, & no sign of any water ingress

It's the same basic idea as the Targa roofs .. bathroom silicone will do the job . Nice going on removing them though .. not something i've had the pleasure of before so ill make a note

You could seal the outside easily if it leaks again tho i reckon your fix should be a pretty permanent solution. For the exit of the drain, it's behind that wheel arch liner. It's like a little rubber duckbill poking down. On your picture, if you follow the inside if the seam sealer down, you can see a little rubber tube behind the liner. i think it might be that?

Thanks for the tip skinny_monkey. The tubes are clear for now, but useful to know where I can check them, should I ever need to

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Resurrecting an old thread just to say thank you! I've had damp musty smells since the end of summer and have just got round to investigating them. No puddles in the carpet and drain tubes not clogged, but damp patches in the top corners at the rear of the headlining. Just took down the back section of the headlining and have the exact same problem you have! If I pour water down the sunroof channel about half of it ends up where it is supposed to under the rear exhaust area, and the other half seeps past that plastic connector and on to the rear seat squab.... been looking to see if I can buy new plastic connectors and looked like only as part of the cassette, then came across your thread and discovered they are removable! What great news!

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Quick question if I may? How much sealant did you apply and whereabouts on the connect piece? I filled the groove across the bottom and around the two short sides with some black sealant, just slightly proud of the top of the groove and refitted the on Wednesday, then put some masking tape around the top of the sunroof just to give the silicon 48hrs to cure without getting wet. Tested it today, removed the tape, opened the sunroof and slowly poured water down the channels... straight onto the back seats! LOL. Cleaned the connectors up again with ISO alcohol and ordered some fresh Granville black silicon (the stuff I had was first a opened couple of years ago) and will take more time to clean out the receiving channels of any grease this time before re-trying. Wondering whether to do the same as I did before, or slather it in Silicon this time!? Cheers

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Just need to say that this post should be pinned with any other 996 leaks, even the garage did not diagnose this issue, and only after following your instructions has this been rectified. Took me hours to find this post, so thanks to the OP for the pictures and details. Many people will start to suffer with this issue, mine is a 1998 996 year of manufacture and the rubber sealant was toast. Thanks!

A video showing whats hidden beneath the headliner and the problem identified here, but missed the solution offered here sadly. Youtube

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Yeah, this video is actually an excellent representation of the issue, they might need to do what I have done to truly fix it!

Really useful, thanks for sharing. I rarely drive in the rain so was surprised to find the back of my passenger side carpet very damp recently. This will come in very handy.

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From the video they seem to have several issues, but it's worth a watch to see where the plastic connectors join the top of pipes to the sunroof drainage channels. On mine the pipes weren't blocked, but there was clearly a leak where the plastic connectors joined to the channels.

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Sorry for the late reply, I hadn't seen your question till today. I didn't go too crazy with the sealant, as I didn't want to impede the flow. I basically just reapplied to the areas where I removed the old stuff, you can see this in the first pic I shared above in post #3. S Post in thread 'sunroof drainage leaking' 13 Jun 2020 Thanks Ian FYI I found the plastic connectors can be removed from the drainage channels by gently levering the clip on the outer edge down. Once removed, You'll see there is a groove around the edge of the connector which is filled with the remains of some black sealant. Possibly the 3m stuff shown in the rennlist guide for replacing the external seal around the edge of the sunroof. I cleaned these up & replaced with some fresh sealant which should hopefully resolve the leak for another 10 plus years. If not it's a fairly easy job to remove them again to renew the sealant. sp1ke I did thoroughly clean the connectors before re-applying all around. I think I used the 3m stuff from the rennlist sunroof guide, as I had a tube to hand. However, as DeMort mentioned above, regular bathroom sealant may suffice.