Fixing Your Audi A6 Water Leak (Video)


Rain has dominated the Shenandoah Valley during the last few weeks. I can appreciate the value of precipitation, since rain = good water levels which = more kayaking excursions. However, the precipitation hasn’t been very kind to my 1999 Audi A6 Avant.

A few weeks ago, I noticed a water leak in the Audi. As I drove uphill, water came rushing through a vent near the passenger side floor. I figured this is one of those problems you can’t really ignore.

Instead of dropping $150+ to have a dealer fix the problem, I decided this was something I would try to fix on my own. The good news for me is that I fixed the problem in less than an hour. The good news for you is that I’m a nice guy and I took some raw video of the process.

I won’t make any guarantees, but this video should help Audi owners who are experiencing similar problems. When you’re done fixing your water leak, feel free to send me a check for the difference.

168 Comments

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  1. 2
    simon

    Hi I have a A6 saloon 2001 which had the same problem but unfortunatly for me the brake servo which sits next to battery sucked the water into the engine braking the engine rods oops! needed a new engine just to let people know it can do some serious damage

  2. 3
    Alan Barrow

    Thats a great little video. I have an A6 02 plate thats getting water in footwell behind the driver but no where else. Have you any ideas?
    Just waiting for some dry weather so I can hose down the back door to see if I can find a leek.

    Cheers Al.

  3. 4
    JWAL

    Hey Al,

    If you have a sunroof I’ve heard of some drainage issues there. This might lead to the water on the floor of the footwell behind the driver.

    Feel free to post another update if you’re able to fix the problem.

    JWAL

  4. 5
    j merrell

    Hi All
    Great video – it was the problem on my A4 Avant – I could not believe how much water was actually slooping around.
    jm

  5. 6
    Martin

    I’ve not yet had this problem on my A6 Avant Quattro but thanks for the heads up. I’ll take mine off and have a look . Many thanks Martin

  6. 7
    SCOTT

    JWAL

    Thanks for that – just going away with the family and the same problem has been bothering me for some time! Many thanks

    Scott in the uk

  7. 12
    Jan Ketch

    Hi – my rear passenger footwell is soaked with water (2000 A6) any ideas on what is causing this or how to attempt to fix the problem? Thanks!

  8. 13
    JWAL

    If you have a sunroof, there are drainage areas there as well that may need to be cleared. I haven’t had that problem yet, but I’ve heard that it’s another Audi flaw for these years.

    Best of luck to you.

    JWAL

  9. 14
    Jan Ketch

    Thanks for the response. I know there are alot of important things under the front footwells but do you know if there is anything electrical under the rear passenger footwell that is in jeopardy of getting damaged? The car is away at school with my daughter who won’t be home for summer for another two weeks – just wondering how urgent this situation is and if it is too risky to wait the two weeks to address the problem?

  10. 15
    JWAL

    I don’t want to mislead you, but I don’t think there’s much to be worried about in that area. If the passenger seat is a power seat, that could stop working, but I doubt it.

    In other words, I think the situation can wait another two weeks. Hope everything works out.

    JWAL

  11. 16
    Jan Ketch

    Just wanted to say thanks so much for your quick responses and sharing your knowledge. I won’t hold you responsible but I really appreciate your opinion as it will help me rest easier over the next two weeks!

  12. 17
    Stacey

    Thank you so much!! This happened to my Allroad and fried my electtical system a year ago. I had just had the windshield replaced & everyone thought it was the windshield replacement (so did the windshield people) & they paid to fix it all. Now – it has happened again today & I actually had super hot water pour on my foot when driving an hour ago and it gushed into the passenger side. Geeze, I’m 8.5 months pregnant & don’t need this. My husband just did your trick & everything that was clogged drained down!! Thanks so much! I’m amazed at your helpfulness!! I love my Audi again!

  13. 18
    JWAL

    Stacey,

    Glad I could help. The Audi is a beautiful car, but this flaw can have some serious consequences if it isn’t addressed.

    Best wishes for a quick delivery.

    JWAL

  14. 19
    MATT

    WHAT HE DIDNT TELL YOU WAS THAT IF YOU PULL UP YOUR FRONT PASSENGER CARPET YOU WILL FIND A BOX WITH THE AUDI’S COMPUTER THAT MAKES EVERYTHING WORK. SOME GENIUS MADE A HOLLOW FOR THIS TO SIT IN AND GUESS WHERE THE WATER GOES. GET THIS DRIED OUT QUICKLY OR IT COULD COST YOU A FEW HUNDRED TO GET UR MOTOR BACK ON THE ROAD. JUST LIFT THE BLACK BOX UP AND KEEP IT SUPPORTED WHERE IT WILL STAY DRY. be very carefull when removing your battery as the stripp at the bottom of your windscreen is another way that water gets in if disturbed. i love my audi but some of the engineering is so badly designed, its very frustrating

  15. 22
    Boticiu Cristian

    Thank you for your feed back.
    Sorry for my english, but i think you understand what i want to say.
    For the moment in my car is dry, even two days ago was raining.
    I hope remain that, i mean dry.

  16. 23
    Marc

    I am having the same problem with my 1999 A6 Avant. I will try your solution tomorrow. I find it hard to believe that a car so well engineered could have a flaw like this. However, I figured there was a simple solution. My audi dealer wants $150 to unclog things. I will let you know if it works. Thanks for the heads up video!
    Marc

  17. 24
    JWAL

    Hey Marc,

    There was a class action suit filed sometime less year for individuals who had to pay for costly repairs related to the flaw.

    Since I solved the problem on my own time, I couldn’t qualify for any payouts. Hope my video helped.

    JWAL

  18. 25
    jc B'ham

    Thanks so much. Had my A6 Avant on a 05 plate 6 months and love it. Realy annoyed that Audi have allowed this to happen. Passenger side F/R carpet footwell soaked. ECU OK though found problem in time. Top Video, WELL DONE

  19. 27
    Todd

    JWAL – wish I would have found your video before I took my car in to find the water issue. Though my Import service guy only charged $60 to unclog the drain, I still have water in the AC system sloshing around. Have you hear of anyway to get the remaining water out of the vents? The mechanic said just to wait for it to evaporate, but its been 3 weeks and I still have water in the dash… Any suggestions welcomed.

  20. 28
    JWAL

    Hey Todd,

    It’s possible that your mechanic didn’t get all of the water out or that the drain reclogged. You can use the video to check out those possibilities.

    It’s also possible that he’s right…there could still be some water trapped that just needs to evaporate.

    The final option is that you have a leak somewhere that’s allowing water in, but I doubt it.

    I wish you the best of luck.

    JWAL

  21. 30
    Matt

    Hey thanks JWAL, I have been getting condensation and this morning could hear water sloshing around when I went around roundabout going to have to leave tonight but am going to have a look tomorrow. Hoping its problem as you show in vid.

    Must admit I have been having central locking/alarm setting problems which only occured when raining so it could have been affecting electrics somewhere.

    Thanks again and appreciate you taking time to post.

    Matt in UK

  22. 31
    jwal

    Matt,

    Thanks for the kind words. I hope the video helps you solve the condensation problem. It’s quite possible that water in bad places would cause the alarm issues as well.

    JWAL

  23. 32
    Matt

    Hi JWAL, followed your guide during lunch today (at work) LOADS of water, it was an inch up the side of battery. There was no grommet but a hole (where grommet should be) which was full of leaves etc, poked through and hey presto it all drained away. Carpets are obviously still soaked but hopefully can dry that out over a few days.

    Oddly there was a pipe, with a right angled tube just hanging around on right side of battery, like a water jet pipe. Could not see where it could fix too. Anyway all is good with reservoir so job done.. Thanks again..

    Matt

  24. 33
    Louis and Stella

    Just wanted to say thank you, thank you, thank you! I had recently purchased a 2000 A6 4.2 and I loved it, at least until the tranny started acting up. I noticed the pool of water on the passenger-side. I looked for similar problems online and found your remedy. I replaced the computer under the floor-mat, opened the plug under the hood and ‘voila’ – problem fixed! Ps: I purchased another A6 .

  25. 34
    JWAL

    Louis and Stella,

    Glad I could help. It sounds like you’ve fallen in love with your Audi(s).

    They are beautiful cars, even with their problems.

    Happy driving to you.

    JWAL

  26. 35
    Bill Cowan

    Yes, a well documented Audi fault, which I also fixed.
    BUT still had water coming in. watering can tests found that it was the ventilation air intake housing. Just under the windscreen over on one side is a concertena style intake air filter. It sits on a crappy plastic housing which has a decayed foam seal underneath. There is a 5mm upstand as well but leaves and crap jammed up under the bonnet(hood) hinge meant water was getting over that and past the seal.

    Remove housing (3x 10mm nuts), clean, dry, slather with silicone = cure

  27. 37
    John Barrow

    Brilliant little video clip
    Just saved me pounds buy not taking it to a dealer

    Two inches of water in rear footwell, thought it was blocked drain holes in the ddor till i searched the sebsite and found your clip

    Two inches of water in reservoir under battery

    Is the ECU in the same placce on the 2.5 Tdi? under the RHS (driver in UK) carpet?

    thanks again

    JB

  28. 38
    John Barrow

    Matt
    I think that little hose is a vent pipe which fits to your battery to take away potentially explosive gases (H & O) from around the battery comaprtment – unfortunatley many batteries (mine included) have the hole to which this ought to connect on the opposite side of the casing ( Dohh !)

    Not a major issue, don’t worry about it

    John B

  29. 40
    JWAL

    Hey John,

    Unfortunately, I can’t answer your question about whether or not the ECU in the same place on the 2.5 Tdi? My guess is that it is, but there are typically small differences between the US and UK versions of a car.

    Some of the Audi forums might be a good place to ask.

    Glad the video helped!

    JWAL

  30. 41
    Dennis

    Got back off Hols on the 17th only to find driver foot well and rear full of water plus condensation. Dash computer also playing plus speedo. Watched your vid and drained water. A leaf caused blockage. I didn’t need to remove plate although the batt was a nightmare. Car in garage as we speak due to electrics. Audi did send a letter out but at the time my car was fine.

  31. 42
    Joe Wrigley

    Dude, you rock.

    I’ve been stressing about the cost of solving this problem on my 1993(?) Audi 100. Water appearing magically in the footwells (especially passenger) and terrible problems with steaming up.

    Thought I was going to have to take it to the garage and spend what could be a lot of money I don’t have and searched around in desperation. Found your site via http://www.audi-forums.com and although the 100 is somewhat different the solution was pretty much the same. Inches of water, also inches of accumulated leaf mould and other crap. Cleared it all out and unblocked the drain. Got a dehumidifier running in the vehicle overnight to help dry it out.

    Thanks from the UK. Your clip gave me the confidence to at least try it.

  32. 44
    Rob

    Got to my car after a night of rain and low and behold a swimming pool on the drivers sdie. Unfortunatly the water got nto the computer and the transmission is buggered. Thank god for insurance.

  33. 45
    Marge

    Thank you! Today we solved the problem our 2001 Audi Quattro A6 was having with water in the interior passenger side. Watched your video and had the job completed in 20 minutes … not bad for a pair of automotive dimwits. No electrical damage, just wet auto carpeting to dry. And the clogging culprit?……pine needles. Much appreciation from the northeast of Switzerland!

  34. 47
    Karen Fichter-Venners

    Thank you for this video. My daughter’s car had this problem and we were able to fix it for free. THANK YOU!!!

  35. 48
    Ericka

    Thank you for that! I’m a woman and my mechanic kept telling me it was a heater core leak and that the fluid that kept dripping on my foot was antifreeze. But I could tell it was clearly WATER and not orange anti-freeze. I had the same issues when driving uphill I would get the leak, it also leaks on the passenger side too most specially when it rains. I have some ammunition with your video now! Thanks.

  36. 50
    Michelle

    I have a 2002 Audi A6 and experienced the same problem.. passenger side filled with water, the water got into the electrical system and its going to cost $2,500 to fix because of a clogged water overflow! I think this is something common GREAT!

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