Hi All
Need some help please.
My Audi a3 has a pan roof.
Its been leaking via the top of the A pillars. Front carpets were soaked too. Ive had the drains cleaned. Didnt help.
Then changed the main seal for the sunroof but the problem is still there. Removed a pillar trim on passenger side but we didnt find and drainage tubes. Does it drain on the drivers side?
Cant find anyone in west yorkshire who can do the job. Any suggestions on what can be done or who to take it to?
Thanks
Hi I have the same problem see Spartacus 68 on 12/09/2022
This issue is well documented. The sunroof is made by Webasto and is used in similar VAG models, such as Skoda, SEAT, etc, so you will find similar threads.
Now it could be the sunroof drains are blocked or are dripping at the exit drain, but in nine times out of ten it's the actual sunroof cassette. I've repaired mine at least half a dozen times, but the repair is temporary. Because the sunroof cassette uses a mix of plastic and metal parts - Webasto used a mastic sealant to sandwich the whole thing together, it's fundamentally a manufacturing design flaw. If they had used a single plastic tray insert such as Volvo for example, we wouldn't have this issue.
The sunroof rubber seal on the glass and bodywork is not designed to be completely watertight. The excess water that seeps through is meant to collect and exit on one of the four drain channels front and rear, however what happens is water pools and eventually finds a way through the mastic area that sandwiches the composite roof.
If you think about it - the car experiences vibration, and extremes of hot and cold every day, basically the ingredients to create a failed bond. The only correct fix is to replace the entire cassette, and because Webasto probably never changed the design, then in another 3-4 years I'll guarantee that will fail too.
What you're seeing is the water dripping from a failed section on the cassette where the seal has opened, onto the roof lining, then eventually down the A pillar plastic trim where it will drip onto the carpet and soak the sound-deadening material underneath.
As a short-term solution, pull the rubber floor mat (assuming you have one fitted) and get paper towelling or a wet vacuum to take up any moisture. Once it's try, get plastic sheeting down until you can investigate properly.
I have been chasing the same fault and have been for the last 3 years. I'm not prepared to pay Audi the best part of £2.5k to replace.
Fixes I have tried included glass-fibre matting, well that didn't work, so I moved onto marine sealants with limited success of anywhere from 4-6 months with no leaks. If you are using a sealant, use tin-foil on top - to separate from the headliner otherwise if you need to investigate again you will be a in world of misery trying to pull apart. Sikaflex make most of the commercial sealants for automotive and marine use including 291i but I'm going to try 591 next or 3M 5200 Marine Sealant.
As we approach winter, it's important to get it fixed, as any trapped moisture will freeze and you'll notice water and condensation on the inside of the windscreen.
Work in a clean well-let environment, or on a decent day when you know the weather will be dry. This is not a job at the end of the day in fading light. The interior grab handle is the worst part, but with the right tool is straight-forward. The interior if light coloured will mark very easily, hence wear nitrile gloves and change them often. You can ease the rubber door rubbers over the roof lining with a bit of persuasion.
