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Unbelievable rain now water in drivers footwell.

S3 GAZ May 20, 2014

  1. S3 GAZ

    S3 GAZ Member

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    Hi looking for a bit of help with my 1.9 tdi quattro sport.

    We had the most unbelievable downpour last night lasting roughly 30mins. The worst rain ive ever seen in such a short space of time. Went out to the car this morning to find the Drivers footwell sodden. The passenger side is fine along with the rest of the car.

    Now i have removed the plenum chamber gromits last year and i found no water in there this morning.

    also I had the car sitting on a slight incline. Im wondering if the ammount of rain was just too much and the plenum chamber has filled and the slight incline has let it come in through the bulkhead.

    Any ideas or know any routes of entry for water in the drivers side.

    any help appreciated
     
  2. swarcup

    swarcup Well-Known Member

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    ECU Box is the ususal suspect on the drivers side i believe, the seals can go letting water in. Worth opening it up to check that the relays and ecu are dry
     
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  3. quattrojames

    quattrojames Moderator Staff Member Moderator Audi A6 Audi Avant Owner Group

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    Seconded, quite a common issue.
     
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  4. Mike.M

    Mike.M Well-Known Member

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    Also check the door drain holes
     
  5. S3 GAZ

    S3 GAZ Member

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    Had water in the ECU box last month causing some starting issues. Cleared water out and redone some wiring and drilled a couple of holes in the bottom of the ECU box

    Obviously the seal must have perished on the ECU cover and is letting water in.

    How does it get from there into footwell
     
  6. Mike.M

    Mike.M Well-Known Member

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    There is a channel of cables that flow into the car from the ECU so the water would just follow them.
     
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  7. S3 GAZ

    S3 GAZ Member

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    Cheers mike. I'll investigate tomorrow. Its a right pain in the tonsils getting that ECU cover off. Gotta remove wipers and that scuttle trim. Arghhhh
     
  8. pauldazzle

    pauldazzle Well-Known Member

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    You can do it without removing the trim. There's actually a small hole in the trim (below drivers wiper) to allow a long torx key to be inserted to get at the bolt below the wiper, & you can use the slots in the trim to get at the other rear bolt.
     
    Last edited: May 21, 2014
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  9. Mike.M

    Mike.M Well-Known Member

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    It is but gives you the best access to do any work
     
  10. S3 GAZ

    S3 GAZ Member

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    Well got the ECU cover off and noticed one of the nuts that secures the ECU tray to the engine bay was missing therefore not creating a seal. I've replaced the nut and made sure its a tight seal now.

    Also got the carpets up and left a hairdryer on the sound deadining for 3 hours so footwell is all dry now. Fingers crossed that's it sorted.

    I think its been leaking for a while as there was a fair amount of water in the foot well.
     
    Last edited: May 21, 2014
  11. Mike.M

    Mike.M Well-Known Member

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    Sounds like you found the cause then. Hopefully no moisture damage to the ECU and wiring connectors with corrosion.
     
  12. S3 GAZ

    S3 GAZ Member

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    Yeh been there last month with it Mike. Had to replace some wiring and replace ECU relay. I must have not put that nut on then and its been leaking since then

    Hopefully it'll be OK now
     
  13. duffy78

    duffy78 Member

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    I had this in my car. It wasnt the ecu box cover that was leaking it was the bottom of the ecu box where it fixed / sealed to the car. the seal had perished around the bottom rim.
     
  14. S3 GAZ

    S3 GAZ Member

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    That's what I found to be it the issue. I was missing a nut that secures the ECU box to the engine bay and therefore there was no seal.

    What was your solution Duffy. Did you get a new ECU box and how much was it ?
     
  15. duffy78

    duffy78 Member

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    My solution was a bit more ghetto than that.

    Bathroom sealant around the upturned rim on the car body that slots into the underside seal in the ecu box. Dry as a bone ever since.

    Interesting enough mine first manifested as an EPC fault in the throttle control.

    The water was running down the cable to the accelerator and was corroding the contact inside the pedal. It had to strip the pedal and clean all the contacts inside.
     
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  16. S3 GAZ

    S3 GAZ Member

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    Brilliant mate. I'll remember that method lol
     
  17. Tim17

    Tim17 Member

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    After the tropical thunderstorm we had today I also have water in the drivers footwell!
    I've only had the car a few weeks but I've read about water in the footwells being a common problem so I decided to check, and, much to my delight, I was greeted with a wet carpet (which I never would of known about unless checking as I have rubber all weather mats).
    So I guess my first place to check is around the ECU box, hopefully it's something as simple as that!
     
  18. S3 GAZ

    S3 GAZ Member

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    No joy Tim. As you say its very common. But there are a lot of electrical components under the carpet in both drivers and more importantly passengers footwell.

    Water in the passenger side is usually caused by the plenum chamber where the battery sits filling up with water. There a 2 drain holes with rubber gromits that get clogged up. Simply pulling the gromits out releases the water and stops it filling up. There one under the battery and one under the brake servo. I found it easier using long reach pliers and pulling them out from under the car and also got a face full of water lol.

    Drivers side as discussed in this thread is generally caused by the ECU box.

    If the sound deadning under the carpet is soaked then squeeze as much water out as u can and mop up with a sponge and then use a hairdryer for a couple of hours and keep moving it around

    Hope you can get it sorted mate
     
  19. Bradazbsak

    Bradazbsak Member

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    Iv had the same sort of problem on y b6 1.8t but my cars bein going into limp , traction light and eml and esp and epc been lighting up on the dash, after a week it stopped doing that now the Esp Abs Red Brake warning and the handbrake lights are all coming up about 2 mins into a drive, if i switch off the ignition and straight back on again and turn off the Esp nothing at all lights up, on vcds at first it came up with brake pedal switch, cleared the code to see what came back and its coming up Throttle position sensor, i know The b6 are know for the plenum grommets blockin up with **** and not draining water and checkin the footwell i could see small drips up on the wires behing the obd socket, when i went to check the plenum grommets i reallised they had already been ****** off so next step was the ecu box seals, so after wrestling with the seized wiper arms and smackin the living death outta them with a socket and hammer i got to the top of the box, i unscrewed the first 2 torx , went to unscrew the 3rd and reallised there wasnt one, already been taken out, and the one behind the back side was snapped off :/ when i got the top half of the casing off i saw a massive hole in it where it has been smashed previos to me owning the car, looking down under the ECU o can see straight into the drivers footwell, i will post a pic of the top half of the casing, how this hasnt caused me massive problems i do not know but luckly iv found the problem, i will order a new casing tomorrow at work as i work at VW and get it fitted making sure its all nice and tight. The water has been dripping onto the pedals and most probably bridging the wires in the throttle and brake sensors. Causing mayhem in the ecu. Hope this helps anyone with the same symptoms not that you will have had your Ecu Box beaten with a sledgehammer before lol
     

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