Audi A6 Avant - Water in footwell problem

[Tazz070299]

Hi Lenny
With water in the REAR footwell it would seem unlikely that is the battery plenum. More likely to be the rear screen washer tube which runs underneath the carpet on the passenger side, next to the door sills. It could be that there is a join, or small hole in the pipe.
I understand that in cold weather, with not enough concentrate of screen washer in the system to prevent the water freezing, the pipe and contents freeze. When you operate the screen washer pressure in the pipe increases because of the frozen blockage, and something gives, dumping water all over the floor.
As others have said, the front foot well is worst, as the water penetrates the electronics and all the fun then starts.

Tazz

[lennymfo]

Hey thanks Tazz, the wettest is on the rear passengers footwell on the drivers side and there is alittle dampness on the rear passenger footwell passengers side. Could this be anything else? Can I unlblock any blockages that there might be? Len

[Peter D]

Both rear footwells ??? Do you have a sun roof. Regards Peter

[buster]

When I moved to Sheffield and had a service done by Gilders, they told me that there was a recall for my car. This was for a plenum chamber check and was done free of charge. (they even washed it and vacuumed my car for me - FOC).

Thankfully, mine was ok, but Audi are aware of this problem, or there would be no recall.

To the OP, why don't you phone your local Audi dealership and just ask if there is a recall for your car?

[Arnot]

I have a 2002 A6 Avant with the dreaded water damage to the comfort module.

The symptoms were; no electric windows, no interior lights, warning signs and buzzer on the dash.

The carpet in the passenger footwell didn't seem wet or damp to the touch.

Underneath the carpet, there is a depression in the footwell with the comfort module located in a plastic box along with it's relevant connectors. The depression had a fair bit of water in it and the moulded foam backing to the carpet was absolutley soaked.

On examination, the plastic box that the comfort module is located in is designed to resist water entering from above but due to the absence of any drain in the moulding, if the water enters from below, it is kept in there. With no ventilation, this water cannot escape or evaporate and so it enters and corrodes the terminals in the connector blocks to the comfort module. Eventually the corrosion reaches a point where the wires part company and the previous intermittent problems become permanent.

On my car, the comfort module had been replaced by an Audi dealer some 18 months ago but the corroded connectors had not been replaced or the cause of the leak corrected. In consequence, the new module is now damaged and the connectors completely rotted away.

I am told by my local dealer (Stafford Audi - very friendly and helpful) that there is a repair harness available but that it is not shown as a spare part in the normal system. They are trying to get hold of one for me though. I have to say that if Audi do actually provide a repair kit for this fault then they must know of the problem...

My guess from looking at the car is that apart from the possibility of the battery compartment holes getting blocked, the major problem seems to be that there is no positive seal between the windscreen and the plastic scuttle that clips to the bottom of it. Moreover there is no top cover listed in the Audi parts system for the pollen filter. As a consequence, whan it rains some of the water that drains off the screen on the left side gets behind the scuttle and drips on to the top of the pollen filter. This then in turn drips into the fan plenum chamber and enters the car behind the dash and under the carpet. Once there it cannot escape and collects under the carpet undetected until it reaches a leve where it enters the comfort module housing.

My suggestion is that as well as making sure that the compartment drain holes are clear is the following;

1) Remove the plastic trim (scuttle) at the bottom of the windscreen and refit it with a bead of black silicon to prevent leakage.
2) Using a piece of butyl rubber pond liner, make a cover sheet for the top of the pollen filter so if any water does fall from above it is deflected.
3) Run a small piece of piping from the rear footwell ventilation under the carpet to the void beneath the front footwell carpet to provide some ventilation for drying out what little damp gets there so it cannot collect over time from damp feet or any leakage.
4) ALWAYS replace the terminals when replacing the comfort module.
5) Drill a couple of small drian holes at the bottom of the plastic box that contains the comfort module so any water that enters by leakage or condensation over time can drain awaly.
6) Apply a little vaseline (not grease) to the wiring connector blocks and terminal prings on the comfort module when re-assembling it to prevent future corrosion.

In any case, that is what I am going to do and hopefully it will cure the problem permanently.

I will report back with details of the wiring repair kit when and if it arrives.

Regards

Arnot Franses


"Highlandspring durch technik"

[lennymfo]

Hi guys my car doesnt have a rear washer and the rear carpet drivers side was quite wet this morning. It hasnt been raining up here for some days now. It only seems to be a bit of carpet next to the middle bit humpy thing (cant think of the technical term) that has the handbrake and the armrest thing. Any ideas?

[lennymfo]

Hey up Peter no, I dont have a sunroof.

[lennymfo]

Hi Tazz, I dont have a rear washer. Its only a small part of the carpet that is wet and the part is right next to the middle lumpy thing.

[buster]

It only seems to be a bit of carpet next to the middle bit humpy thing (cant think of the technical term)

Transmission Tunnel?

ok - it's not a transmissional tunnel unless its a quattro, but that is generally what it's called.

You need to check the rubbers around the rear doors.

And also the top of the rear window across the back of the car. I take it that it is a saloon and not an estate.

Is the water clean?

If you touch it and touch your finger onto your tongue, does it taste sweet?

Does is smell of anything?

[Peter D]

Actually on the A6 the gear box is in that tunnel. However Lenny you need to check the Plenum Chamber forst. Was the screen with a hose for 30 seconds then lift the bonnet, remove the battery cover and look down the RHS side of the battery with a good torch if you can see water then that is probably the proplem. There are recess in the floor on both side to take the heater duct to the rear passengers and the recess continues to the rear of the footwell where there is a bung covered in underseal. There are three places that can let water in The plenum Chamber filling up and sloshing water into the open pollen filter and running down into the heat fan assembly and into the car via the airducts. This tends to put water on top of the carpet. The secong is a failed seal under the pollen filter housing and this lets run off water seep into the outer of the air duct and it creaps behind the carpet and eventuall gomes out just behind the rear heater vent, the third is a crack or seal failure in the Engine ECU housing on the other side to the pollen filter and wets the drivers side and somtimes when first moving the car after rain you feet get wet. I did a Passat ( same floor pan) week before last and it was a perished seal under the pollen filter, pulled the rear bung out and water poured out, either put the car up on ramps at the front or perhaps your drive is sloped. It take several days to dry the carpets and underfelt out. Regards Peter