2001 S8

Hey D2 Owners,

I was told my sunroof drains are partially clogged and it was recommended I have them cleaned. I want to do this job myself. Where in the sunroof are the drains? How do I clean them; will compressed air do the job?

Thanks in advance for any advice.

twentysevenlitres

Very common on D2's.

Plenty of "how to's" around the place to show you where and how...

There are four sunroof drains, two front and two rear.

The two rears are the largest and therefore I think "main" drains.
They are located either side of the interior of the boot (trunk) just behind the wheel arch.
The right hand one is very easy to find. Pull the battery cover off and look towards the front corner of the battery and you'll see the tube (mine's blue, but that doesn't follow that they all are).
It exits the car via a fitting which is a press-fit into the side panel of the boot. The tube pulls out of the fitting, and the fitting pulls out of the side panel of the car.
Be careful pulling the tube out, as if it's full of water it'll gush out over the battery and into the crevice below where the central locking pump lives!

The fitting itself is the root cause of the blockage, as it consists of a plastic "+" shaped nipple on the end which was designed by Audi to stop debris entering the drain tubes or car. That same feature gets blocked by the very debris it's designed to stop!!
Now, this part is up to you but you now have two choices. You can clean up the nipple to try to get it functioning again, or the more common approach is to trim the nipple off completely as it will only block up again!

The left hand drain is in the same location, but it's just a bit harder to get at behind the entertainment gear.

Be sure to inspect all under floor cravices in the boot (trunk) as they will fill with water when the drains are clogged and drown such things as the central locking pump, parking sensor ECU, and Bose amp (where fitted).


The front drains are less likely to block, and can be inspected just above the front door hinges with the door open (lower A-Pillar).

If cleaning of the tubes is necessary, use compressed air, or an item such as a bicycle brake cable (sans wire!).


For future reference, the plenum area below the windscreen has four similar nipple drains (two in the rear of the front wheel wells and two above the transmission bell housing area) which get blocked also - potentially drowning the ECU/TCU and causing interior water ingress.
There is also two nipple drains inside the passenger compartment for the airconditoning condensation to drain. These are on the transmission tunnel up near the firewall on both sides, accessible behind the carpetted side trim above the floor mats.

2001 S8

Thanks for the quick reply twentysevenlitres. Definitely agree about the amount of great info on this forum.

I cleared the front wheel well drains last night and based off your posting on 11/8, I was able to locate and clean the passenger side drain plug. I pulled out the blue drain tube from and used a plastic straw, pushed through the nipple and blew compressed air through it. I am little gun shy on getting to the driver's side drain. I have the nav system and disc tray to remove or get past.

I need to check where the water enters the drains in the sunroof to make sure those areas are clear as well.

On a side note: Since I installed new plugs on Friday, I have notice an improved throttle response at all speeds. So now she's more responsive and smoother. That is a Win-Win.

Thanks again.

twentysevenlitres

That's good news, glad I could help!
You really need to get to that left hand side though - it's not that difficult.
And I'll guarantee if the drain is blocked the cubby hole under it will be flooded and that's where the BOSE amp and parking sensor ECU live.
There's a couple of bolts hold the side moulded trim in place, then the entertainment gear comes out in two frames IIRC. Everything unplugs and the plugs are all unique to their component (don't be too concerned about the 4 round ones in the TV reciever (if fitted) they're just the aerial plugs). There's only about 6 bolts total, then you have full access.
You can probably get to the drain just by removing the top frame, but then you won't be able to get to the cubby to rinse the water out!

I've still yet to put my iridium plugs in - and perform a service and fix a couple of niggling issues for that matter. I've been slack!
The weather down here has been rubbish for about 3 months now - a week of rain followed by one or two nice days then back to rain again! It's been driving me nuts, our Spring's normally have better (and warmer) weather.
I haven't been able to time my days off with the nice weather! That's my excuse anyway, being a hobbyist machanic, I don't want to force myself into the job and turn it into a chore

2001 S8

I kept doing some digging on "leaky sun roofs" and ran across this issue and fix.

https://www.audiworld.com/forums/sho....php?t=2163507

I checked my "water channel" and indeed it had broken off at some point and was stuck at the back of the roof. The "water channel" is made of metal so I used a retractable magnet pick-up stick to retrieve it and move it back in place so the "water channel" can do its job until I can fix it. By doing some inspecting, I think I can fix this on my own and keep some money in my pocket and water off my head : )

See link below for self fix-it directions.

http://forums.quattroworld.com/s4s6/threads/10010.phtml

Hope this helps anybody dealing with water entering the cabin.