Help - Water leak into drivers footwell, but it's NOT the plenum plugs

[Stonedofmoo]

Hi guys

Long story short, the drivers footwell and rear footwell are getting soaked whenever it rains.

I've bonded the ECU cover and removed the plenum plugs, then spent considerable time drying the carpet and underlay, and after just one day of rain and a few miles driving the footwell is soaking again. Exasperating to say the least and this issue is getting on my nerves now. You do a search on this issue and 99% of the time people say ECU cover or plugs.

Any ideas, it's a saloon and there is no sunroof. The door seals are fine and I adjusted the door latch area to ensure good contact earlier in the year.
Short of a leak from the front windscreen I cannot see where else it get's in so easily.

 

[NHN]

Pollen filter area checked?

 

[Stonedofmoo]

Hmm not lately, but I changed that filter a while back and didn't see anything unusual. Also that's the passenger side which remains dry

Appreciate the suggestion though.

 

[NHN]

No chassis holes under or plug holes in floor, some chassis have rubber grommets in the floor pan, but I can't recall from the 8E.

Door seals are common but you've said it's not.

Have you tried the hosepipe method for tracing?

 

[Stonedofmoo]

No chassis holes under or plug holes in floor, some chassis have rubber grommets in the floor pan, but I can't recall from the 8E.

Door seals are common but you've said it's not.

Have you tried the hosepipe method for tracing?

Hi there, thanks for the advice.

I don't believe it's the door seals, they're visually in good condition and the drains on the doors are clear and open for water to drain through; also the carpet by the doors is dry whereas I'd expect it to be damp if that was the path the water was following.

I got into the footwell with a torch this evening. Having removed the plastic door frame trim, and the plastic tray under the steering wheel I can see up into the footwell and underneath the carpet which is soaked through; there is' actually a void under the carpet that was water pooled in!
I pulled the carpet back a little and found a thick block of foam about halfway up the back of the footwell, approx where your toes might be while using the pedals. This piece of foam is wet through and I could squeeze water out of it, it's also far above the waterline with no path for the water to rise up from below, so I'm confident the water isn't coming from the door area.

That presumably leaves the ECU cover on the drivers side, or the windscreen. I got my wife to pour some water from bottles onto the scuttle area and the windscreen and neither resulted in any water coming down into the car. Unfortunately I don't have a hose as we live in flats, but I'm going to go round to a friends tomorrow and use his to see if that makes a difference.

I can actually see the black auto sealant around the base of the ECU cover from inside the car, so I'm positive that I made a good seal when I sealed it up in January.

Is there any other entry point water might get by? The only other thing I could think of was there must be a point the bonnet release cable comes through the bulkhead? Probably too low for water to get through but I'll see what I can spot tomorrow night.

 

[DanisXatzi]

Did you check in the battery compartment if the rubber plugs are gloged?

 

[Stonedofmoo]

Yes, they are the plenum plugs I mentioned. I've actually removed them altogether.

OK this evening I got right into the footwell. Glued to the back of the footrest and going right up behind the dashboard is a thick olive green piece of sound deadening foam. This foam is soaked through right from the top down when towards the back near the bulkhead. I cannot reach the higher up areas of the foam with my fingers as there is a plastic fuse/relay holder in the way, so I prodded it with a stick and can see the water in the foam where I press it in (like squeezing water in a sponge). The trouble with this foam it obscures the path of the water leak.

What I am 95% certain of, is it is not the ECU cover I sealed in January. I had a friend hold a hose and soak the cover for minutes at a time and I didn't see a single drip come down from the ECU cover. The foam surrounding it however is soaking wet so what does that leave? The water is clearly high up so if it's not the ECU cover that surely only leaves the windscreen, perhaps with water coming down from the A pillar area?

I'm considering calling a windscreen company tomorrow and seeing about getting the windshield removed and resealed just in case.
I assume the plastic and rubber trims that surround the glass don't actually stop water in themselves? I imagine they are there for cosmetic and shielding purposes?

 

[DanisXatzi]

you have to remove the hole carpet in order to find the leak and to let the carpet dry.
If you follow from the footwell of the driver side its the ecm box witch includes some relays.
Remove some things so you just can see what is going on.
Yes the plastic doesn't have any problem with selling

In my case in different a different car that was having water, after a lot of hours searching we ended up finding that the water was coming from the speaker housing from the door because it was broken. So the only way to find it to check it with a hose

 

[Stonedofmoo]

Removing the whole carpet and therefore seats etc isn't a practical solution for me. Aside from the lack of garage to store it all in, I use the car most days. Plus the sound insulation deadening insulation is glued into the bulkhead from what I can see.

If I can get the leak sealed I'll dry the whole area using a wet vac.

Change of subject, what path does the water from the roof channels follow? I'm assuming it passes right next to the windscreen edges as there is a gap ..

 

[DanisXatzi]

No its not glued.
Yes it goes behind the black plastic trim

 

[Stonedofmoo]

As an update to this, I am 99% certain I have fixed it now. The drainage channel that runs down past the windscreen on the driver side was completely blocked at the bottom with silt build up. I only discovered this after removing the rubber trim that clips over that channel.

Clearing the channel out so water drained down correctly immediately improved the issue, but didn't completely fix it in heavy rain. The windscreen cannot be totally sealed on the bond. It's an original Audi screen but an old car and I'm sure the bond doesn't last forever, or it's been badly resealed in it's past. Because of this water is getting in past the screen and leaking somewhere down the A pillar/cover and running down to the noise insulation below, where is finds it's way to the footwell in time.

Anyhow after being quoted £145 to re-bond the screen, or £285 to replace the screen if my existing screen broke on removal, I decided I'd work around it by sealing that edge of the screen myself. I bought black silicone for car window work and simply squeezed an extra silicone seal into place putting a silicone wall in place between the screens edge, and the water channel, but leaving it clear to drain.

I'm not going to lie it was a messy job as there isn't a huge amount of access and it took me three sizeable beads of silicone to get the gap between the raised screen and the bodywork filled, but luckily I had a spatula that got the silicone in there nicely, and panel wipe cleared away any excess that was where it shouldn't be.

Time will tell now if it's completely fixed. If leaking continues I'll have the screen professionally re-bonded, but I reckon my £7 bodge will work just fine.

 

[norris_309]

Hope you've sorted the issue,
Funnily enough, i came on here to have a look at possible leaky spots on the B6 as i've noticed damp/wet carpet in mine last week.

Mine is the passenger front & back footwell.. so instantly thought it has to be the plenum drain under the battery.. had a look & it's all dry there. no swimming pools.
However the drain hole under the battery was totally covered in leaves & crud, so cleared that all up. I'm hoping it was maybe just too slow draining with the heavy rain we've been having and the drain hole being covered?... here's hoping.

 

[Stonedofmoo]

Yeah that will almost certainly fix it, but on the passenger side you also have the pollen cover to consider, and the Aircon drain pipe which is in the passenger footwell.

 

[Stonedofmoo]

I was wrong and my repair did not fix it. What DID fix it was a new windscreen, since then no leaks!