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Audi A6 The mid-sized Audi A6 model offers more room to the driver and passengers over the A4 line.
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Old 10-28-2008, 04:27 PM
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Default 2004 A6 Water Leak Pass. Front

My 2004 A6 is getting water inside on the front passenger side. I removed the battery and cleaned out the drain. I do not have any water inside the front trof under the hood. Anyone have any ideas where else I should look. I read something about clogged moonroof drains not sure if my Audi has any.

Old 10-28-2008, 06:54 PM
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I am betting that the sunroof drains are clogged. Audi has a long history on this issue.
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Old 10-28-2008, 07:59 PM
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Thanks for the reply. How would I check if the Moonroof drains are clogged. I don't see any staining on the headliner. Do you know how the drains work I don't understand what is the need for drains when the moonroof is closed .

Thanks again
Old 10-29-2008, 08:15 AM
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Due to the location of the moonroof, it is susectable to water leaking past the seals, so all auto manufacturers add a gutter around the inside of the moonroof to catch any leaking water. this gutter drains down the infamous moonroof drain tubes that get clogged (on any car) by leaf material, rust flakes, spider nests, mud daubers, etc. Ususally, the water just runs down a different drain tube (you have four of them). If you park at an angle, water might overflow the gutter instead. Due to surface tension, water will follow whatever it can as opposed to dripping, so that would explain why your headliner is not necessarily wet. Of course, your drain tube could also be broken somewhere in it's path, which would also explian why the floor is wet but not the headliner. Or, it could be a windshield leak or a plenum leak (the plenum is where the battery is).

Start your car and turn the fan on high. take soapy water and cover the car in it. Look for bubbles. This will indicate an air leak, which is a potential water leak.

Get an air hose or a can of air. Blow it into the right front moonroof drain hose. Does it blow through OK? If not, you have a clog. If it does, feel around in the passenger side while blowing the air and see if you feel the air coming out. You should not.

THis should get you close to resolving your problem.

Good luck,

Old 10-29-2008, 10:59 AM
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Thanks for the reply Bob I'll start looking. Just one question where are the moonroof drains I guess the roof has to be open to see them. Thanks again
Old 10-29-2008, 11:36 AM
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Don't rule out the very common clogged battery tray drain. That gets blocked with debris over time, water fills the tray, and leaks into the passenger compartment through the cabin air filter.

A good DIY post here on AudiWorld (with pics):

Whatever the cause, fix it!!! There are a few essential control modules (TCU) under the carpet. Water and electronics do not mix!!!
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Old 10-29-2008, 11:44 PM
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I un-clogged mine today thanks to this post. (and didn't have to reset the radio).
Great piece of info.
thank you
Old 11-12-2008, 08:53 PM
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Posts: 59

The plug under the battery is clear. I tested my sun roof drains by pouring water in the drain area on passenger side of roof. The water fell right out of the drain opeinings between door hinge right where the water is ment to drain. But I am still getting water inside passenger floor area. The plastic shield under the hood is in place and shielding the cabin air filter correctly. My windshield was replaced a few years ago, so I think this could be the source of my leak ???

Old 11-12-2008, 08:53 PM

2002, a4, a6, a8, audi, audiworld, drain, drainage, leak, location, moonroof, plenum, problem, sunroof, water

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