A6 Avant water noise on the sunroof

[Nicoita]

Hello guys, I have recently bought a pre-owed Audi A6 Avant S-line 50 TDi.
The car has 48.000 Km – February 2019 and it is equipped with the panoramic sunroof.
When I wash the car or drive it after the rain, I clearly hear noise of water moving from one side to the car to the other, and this on the roof most probably.
The noise goes after around 10 km and some bends.
I have done multiple tests washing only the lower part of the car and I can confirm the noise is present only when also the sunroom is washed.
I have read the Audi technical manuals and performed the test to check if the drains hoses works correctly, and it seems to be the case.

– Use a measuring cup -1- to slowly pour 0.5 ltr. of water into
guide rail on each side close to open glass panel -arrow-. Work
carefully to ensure that the water does not overflow into the
dry area of the vehicle. Make sure that water is distributed in
both directions so that both water drains (front and rear) can
be checked.
– At underside of vehicle, check that water flows out in the area
of both the front and rear wheel housings.
– Repeat procedure on opposite side of vehicle.
– If no or only a little water flows out of the appropriate drainage
points, clean water drains ⇒ General body repairs, exterior;
Rep. gr. 60 ; Water drain hoses; Cleaning water drain hoses .

Today I washed the car and immediately opened the sunroof to see if some water was present, but nothing apparently … of course the noise was present
I have no water into the car, but I would like just to know if someone of you experience the same problem.

Thanks in advance for your feedback!!
Nicola

[FBAnder]

Hello guys, I have recently bought a pre-owed Audi A6 Avant S-line 50 TDi.
The car has 48.000 Km – February 2019 and it is equipped with the panoramic sunroof.
When I wash the car or drive it after the rain, I clearly hear noise of water moving from one side to the car to the other, and this on the roof most probably.
The noise goes after around 10 km and some bends.
I have done multiple tests washing only the lower part of the car and I can confirm the noise is present only when also the sunroom is washed.
I have read the Audi technical manuals and performed the test to check if the drains hoses works correctly, and it seems to be the case.

– Use a measuring cup -1- to slowly pour 0.5 ltr. of water into
guide rail on each side close to open glass panel -arrow-. Work
carefully to ensure that the water does not overflow into the
dry area of the vehicle. Make sure that water is distributed in
both directions so that both water drains (front and rear) can
be checked.
– At underside of vehicle, check that water flows out in the area
of both the front and rear wheel housings.
– Repeat procedure on opposite side of vehicle.
– If no or only a little water flows out of the appropriate drainage
points, clean water drains ⇒ General body repairs, exterior;
Rep. gr. 60 ; Water drain hoses; Cleaning water drain hoses .

Today I washed the car and immediately opened the sunroof to see if some water was present, but nothing apparently … of course the noise was present
I have no water into the car, but I would like just to know if someone of you experience the same problem.

Thanks in advance for your feedback!!
Nicola

It probably is the drains. I know the old coat hanger tricked worked on older Audi models (push it slowly into the drains and move it back and forth gently to free up anything stuck in there), not sure on newer models. Have you checked the tailgate?

[turboale]

I would definitely check the tailgate. I was told by my dealer that it is "working as intended" by holding water in the upper vertical portions of the tailgate. Then they "only have a fix" if water penetrates into the lower section of the gate.

[FBAnder]

I would definitely check the tailgate. I was told by my dealer that it is "working as intended" by holding water in the upper vertical portions of the tailgate. Then they "only have a fix" if water penetrates into the lower section of the gate.

Another interesting tidbit about the RS6 that makes me scratch my head a little bit. I have more than once gotten bit by water in the upper portion of the tailgate blowing into me andor into the hatch on a windy day as it drains down the sides. Super annoying. I was also told by my dealer the water retention and draining down the sides on open is by design.

[Nicoita]

Hi gents,

just to give you an update about my “problem”.
I brought my A6 for a sunroof service, they have cleaned up the drains and … surprise … nothing changed.
I have also tried to clean them up and it seems water is well evacuated.
To be noted that respect to the C7 that has 2 drain holes in the front of the sunroof and 2 on the back, terminating respectively on the front and real wheels, the C8 has 2 holes in the back and 2 in the middle of the sunroof and they are connected with a “Y” connection ending on the rear wheels.
This Y connection made the service much more complex, knowing that the holes are not accessible from the sunroof, but only from the rear wheels.
It look likes the water is moving somewhere in the sunroof for few km till finding the holes and being evacuated.
I have also washed the car and opened the tailgate to see if there was any link between it and the sunroof, but nothing changed.
Is any of you equipped with the sunroof able to confirm if he experiences the same issue?

Thanks in advance for your feedbacks!!