I have just been told by a reputable Audi ex-mechanic that the cassette is made from three layers of plastic and these delaminate. So I have just been quoted £2100 for a new one. Although wondering if anyone has a repair that works. 

Possibly! If yours had the same problem as mine & most others then yes. Have a search (use ‘everywhere’) of the forums & you should see my post and a link to the U-tube vlog I found.

its awkward to access but I managed it on my drive. You do need somewhere dry though!

I’ll try to find my other post tomorrow but feel free to remind me as I’ve got ACC issues (it’s stopped working! 1st attempted fix today didn’t work) that’s occupying my mind!) 

Search for:- ‘leaking panoramic roof’

Here’s the link to the u-tube video, it’s good & there are details below of how & what I did.

https://www.youtube.com/attribution_link?a=xVZFIwLIRPdg4dKl&u=/watch%3Fv%3DLJtU3fV22tE%26lc%3DUgwEOIOc62jI3G1NIyp4AaABAg.A-jZYkZKSffA-lG_ogQjfz%26feature%3Dem-comments

We get this leaking into the car when the drains get blocked, even partially, so clear them 1st (see below, net curtain flexible rod is perfect)

if you can find my original posts, I put some more details of how to access the front edge of the sunroof cassette.

if you open the sunroof and look down from above, the wind deflector has a thick hard rubber seal along the bottom that just pushes into a trough in the cassette. (It’s about 4-5mm wide)

that trough has a series of holes in the bottom.  Daft idea but assumed it saves a little weight.

the wind deflector seal seems to lift a bit at the corners, allowing water to seep under it & run into the headlining through the holes. (Mine showed evidence of dirt & dust for about 4-5 inches from each end on the underside of that seal)

i took the wind deflector off, (bit fiddly with the 4 springs, 2 coil springs & 2 leaf springs). I used white spirit/turps to thoroughly clean & degrease the trough & wind deflector seal before using the silicon.

to remove the wind deflector I just used a small flat blade screwdriver to gently lift one end then carefully peeled it off by hand,  it’s an interference fit at the factory (unless a previous owner has siliconed it in) so lifts fairly easily, be careful not to distort it as you lift it out, it’s fairly stiff anyway but the less distorted it is, the easier it will be to put back.

i then released the headlining from the top of both front doors (you’ll need to take the grab handles off too), so that  I could get at the underside of the trough. 
 

I then taped up the holes as far as I could reach, then used a black silicone sealer to partially fill the trough from above, the tape stops it going under the sunroof cassette and staining the headlining.

I didn’t put much silicone in. About 1-2mm in depth  & spread it as evenly as possible with a small screwdriver, one with a blade the width as the trough is best, as the silicone will get pushed about when you put the wind deflector back in. You need to do that before it goes off, putting all the springs back as well.  I used a piece or wood & a plastic mallet to ensure the wind deflector front seal was well seated into the trough as you need to make sure there’s no air gaps left under it .

i also taped up & put the silicone into the 4 holes for the 4 springs. Just make sure you put them back before it sets and then check from underneath to make sure there’s no gaps in the silicone there. 

i then left it for a day to dry before I removed the tape, I also kept checking that the tape stayed while I was putting the silicone in the trough.

if water was collecting in the cassette, it’s likely the drains are blocked, I used a length of flexible net curtain rail (it’s basically a coiled spring with a plastic outer sheath), it fits perfectly int9 the drains. You can see the front 2 at the front corners of the cassette with the roof open, the back 2 you’ll need to access the drain behind the rear wheels, (you should see 2 small Dia hoses hanging down). I just fed the net curtain rail through all four to clear out any debris.

i also covered the sunroof with a waterproof sheet while it was drying.

it can be messy, but it’s if you can find the other thread t has more detail about it. Small screwdriver, small snipe nosed pliers ( for the springs), there’s very little space above the headliner for your hands, so getting the tape on under the holes is fiddly.

just take that bit slowly, you don’t need to remove the A pillar trim but it helps although d advise against it due to the airbags plus they are a pig to get out & wires to put back, that also caused an air bag fault that needed resetting at a garage.

there are also curtain airbags on most cars above the drivers door, so be very careful there. As long as the ignition is off, they are safe, just be careful. Nothing sharp!

I have a set of plastic trim tools which helped a lot, they’re cheap enough online.

 

sorry its a bit long winded but there’s a lot involved, none of it is difficult, but most of it is awkward to access & a fiddly (springs, getting yr hand between headliner & cassette with tape etc) 

but, it did work, haven’t had a problem since.

ill dug out the tube of silicon I used for the name, it’s an adhesive sealant rather than just silicone, so will stick to the cassette & wind deflector better than just silicon.

good luck.

Previous sunroof leaking question was posted by T6NYY, with a title of ‘LEAKING PANORAMIC SUNROOF’.

hopefully you can find that too.

Not sure if this will take it to the other thread.

 

Hi guys, as a sunroof installer of 40 years almost I've had to repair many problem sunroofs. However the A6 sunroofs have same problems as all VW group vehicles as they are made by the same company .I started repairing them about 9 yrs back and  eventually found 8 leaks on each side of the sunroof but not every vehicle leaks through the same point(s)...however to avoid customer come backs I now do all known leaks on every panoramic sunroof I repair so that I can guarantee its waterproof when done .my workshop is in East Kilbride and I have had customers from all over UK  including independent Audi dealers .contact details are on the FB page (E.K.Sunroof Centre) hope this helps. 

I have just successfully completed the process of sealing the lower edge of the wind deflector mechanism and may reports that leak is fixed as tested by a garden sprinkler showering the car for half and hour.

So many thanks to all those who have contributed to this fix.

A couple of points:

I have removed the pair of spring steel components that sit at the end of the wind deflector curtain so that I could seal the pocket that they sit in. That said the sunroof operates perfectly without them. Not sure what their function is, but perhaps as an anti-rattle for the sliding panel? Anyone?

I dropped the headlining on the passenger side mostly so that I did not have to remove the trim and potential damage the airbag on the driver-side A pillar. With Sun visors, grab handles and the central overhead control panel removed I could just about apply gaffer tape to the underside of the perforated mounding that holds the rubber seal of the fabric air deflector, this as recommended here prevented any leakage of sealant to the underside.

The sealant I used was a “ modified silane” or MS sealant/ adhesive such as CT1, but many MS sealants exist now and are popular as they have a moisture curing capacity and don’t mind damp condition. I placed the mastic gun tube in warm water for 30 minutes to make it flow reasonably freely as it was 4C outside when doing this.

Again thanks to all contributors, demonstrating the power of the group.

This repair was on an A6 C7 Allroad 2016

 

Glad it’s fixed! Nothing like wet carpets is there!

It’s a very strange design, almost as if VAG wished to devalue older cars with sunroofs. I think that the rubber seal at the lower edge of the fabric air deflector shrinks laterally opening up at each end a “gutter” with the drain holes in it? Why the holes is a complete mystery.

perhaps a greater power may explain?

I did wonder if the holes where there to make the sunroof cassette a bit lighter, only possible reason I could come up with but its definitely not a clever design!

Morning all.

I am having the same issues on my 2014 A6 C7 allroad, does anybody have a pictorial account of the wind deflector removal ?

Hi Steve, if you scroll up this thread, there’s a very long account of how I did it (dated Dec 2025), along with a link to the U-tube video I found & followed.

i used some ‘JB Weld’ Black silicone adhesive sealant in the wind deflector slot to stop any water getting in & hold the deflector down.

(i suspect it’s the deflector distorting very slightly over time that allows the water to start seeping in, that brings dust & dirt & it just gets worse.)

There’s also an account from Photon on his repair fir this problem.

youll need somewhere dry to do it otherwise the silicone won’t cure or stick to anything.

good luck.

Edited February 15Feb 15 by 56Doc
Omitted info

May I recommend to anyone with this leaking sunroof issue to completely remove the headlining as I feel that this is necessary to fully seal all the points of entry around this strange Webasto Sunroof insert. Its a pain removing all the grab handles, sun visors although the rear rooflight cluster can remain in place as it comes away with the healining.

Once the black plastic frame is easy to access simply caulk each of the slots with a suitable sealant ( I used a MS Sealant similar to CT1)

I also removed the two springs that assist with the "pop-up"and sealed the square holes beneath as the seat for them also acts as a leak point.

100% dry now after significant Scottish Rain

Webasto. What are these slots and holes for?

I managed it without totally removing the headlining. Apart from anything else, disturbing the airbags can be an issue. I only disturbed the left A pillar trim & that caused an airbag warning light.

If you disturb all the curtain air bags too, apart from the risk of setting one off, it’s likely to bring up more faults, that’s assuming you avoid damaging any of them.

It makes the job a lot longer too!

I put a detailed report of exactly how I did mine further up this thread & managed it over 2 days on my drive. (Sealant needs 24hrs to set & I wanted to test it before putting everything back,)

But good luck to anyone that’s still got issues. It can be done at home cheaply with some patience!

I did try it without removing the headlining. With it hanging down on one side the car was unuseable and, of course, I missed a leak after re-assembly so I really do recommend full removal. Its not too difficult and the car is driveable while you confirm to your satisfaction that the leaks have been stopped. Good Luck!

Hi guys, we are doing the same repairs to all VWG panoramic sunroofs and there are eight leaks on each side of the roof .once done its guaranteed. Facebook E.k.sunroof Centre. Or call 07850 335008 for more details .

Liam .