[Communist]

I had a big pollen filter housing leak in late August. the seal at the back had crumbled away, let about 4 litres of water through into the carpets during a big storm. I had to take the carpet out in order to dry it all properly.

My father found some sponge tape like the original seal, and we put that on the pollen filter housing and covered it in roofing sealant. Now I can pour water over the back of the housing and it wont leak through into the inside.

However, water is still getting soaked into the filter somehow. Since it isn't the seal any more, I'm at a loss as to how. It's as if the water is going into the big lip at the bottom of the filter housing, soaking the filter from the bottom, then climbing the filter and dropping behind the grille and going inside.

The filter is installed properly and pushed as far back in the housing as it will go. The scuttle panel is also clipped correctly into the windscreen.

What do you suggest I do next, rip the housing out again, or try and cover the front over somehow?

 

[mondy zetecs]

I have same problem but not yet sealed the pollen filter tray housing.

I tried removing the cowl at the bottom of the windscreen and found underneath the 3 drainage holes the gutter or drainage channel was blocked and came away,could this be where it is leaking onto your pollen filter and into the footwell.

 

[Communist]

Thanks. I checked that little drain channel a little while ago, and it was clear. A few days after your post i checked it again and it was completely blocked. Cleared it out, but car still leaked.

Today i took the housing off again, to try and use a thicker bead of roofing sealant. Hopefully this will keep the water out. Will report back when its gone off so I can test it.

Fortunately we haven't had too much heavy rain since august, so most of the water that's got in has been clean tap water from the hose.

 

[raynkar]

Communist, if I remember correctly (I might not, so am adding that bit ) you went to great lengths to waterproof the pollen filter and its housing. If that's the case then you were fixing something that didn't need fixing. If the parts around the filter are fitted correctly the car won't leak even with no filter in place, which is why the filter isn't the area to sort.

The first thing to do is to ensure that the water isn't coming from places like water drain channels.

What I would suggest is that you ensure all the parts around the filter are correct. Mark the parked position of both of the front wipers and remove them. Next remove the two cowl trims. Next remove the thin black plastic trim from the bottom of the front screen. If you have no trim there you will have found what is leaking lol.
Before you refit the windscreen trim and two cowl panels give them a really good clean and remove ALL dirt from any channels and rebates. Once the parts are together again you can test them by running water down the front screen.

Of course, while you are doing all this make sure the flexible rubber trim is in place at the front of the two cowls, and also make sure the area at the base of the bonnet gas struts aren't blocked with leaves.

 

[raynkar]

Add on to the above.
While it's entirely possible to replace a pollen filter by only removing the passenger side screen cool the job is better if the wipers and both vowels are removed as you are doing the job properly and not just making do with a small opening and unable to move the cowl trims enough to reseat them properly

 

[raynkar]

This isn't the best pic, but you can just about see that the join in the centre where the two cowl covers meet is exactly right, and that the flexible rubber trim strip is in place and in good condition

 

[raynkar]

This shot shows the black plastic trim at the base of the screen. This needs to be in place, but doesn't need to be glued or anything is is needs to move with the cowls as the car flexes.
It also shows just how tight a fit against the screen the drivers side cowl is. It's common for the passenger side cowl to not fit correctly into the screen base trim if it has just been pulled open enough to get to the pollen filter



I've just realised the pic also shows red tape marking the wipers parked position

 

[raynkar]

This shot shows the pollen filter, and that if water is introduced from above (between cowl and screen) it will clearly enter via a paper based filter.

It also shows a tray that is visible at the bottom left hand side of the pollen filter. Does your car have this?

 

[Communist]

I cleaned the strip and all the parts it slides onto when it first leaked, and it is still clear. It is pushed right up against the windscreen tightly, However i suspect water can still run underneath it.

I know it originally leaked through the seal because it had completely disintegrated. However are you suggesting that water isn't even meant to contact the seal, because ALL water which runs down the passenger side of the windscreen cannot enter the pollen filter area because it is blocked by the strip?

Yes - my car has the tray.

 

[raynkar]

I'm not getting what you are saying in the above post.

Which seal had disintigrated?

What I'm saying is that water shouldn't hit the top of the filter from above as the screen strip makes a seal with the cowl trims that prevents this. Water IS supposed to run freely past the front of the pollen filter but not enter it. It SHOULD enter with oncoming air via the vent in the front of the drivers side cowl (which is out of the direct airstream when driving) and then the water should drain at the left and fight hand edges of the cowls while the air will split between going into the filter or out via the two water exits.

The whole reason the air I let vent is offset is obviously because the filter isn't waterproof.

I have no idea if that's what you are asking. Feel free to come back with more questions

 

[raynkar]

Your cowls are screwed down at the front again aren't they?

 

[Communist]

I think I see what you're saying.

I have a feeling that the plastic strip I have has worn out and isn't tight enough. I'm not really sure how it is meant to hold water out as it is quite thin, but it has to work otherwise it would have leaked before. The cowls are screwed down yes, but I think the threads on the bulkhead have crossthreaded, they dont tighten much.

The strip also doesn't run the whole length of the screen as it hits one of the wires for the heated screen which will not budge out of the way. However this is past the pollen filter so hopefully isn't a problem.

I did run a bead of roofing sealant across the top of the passenger cowl just in case, I still dont know if that has made a difference yet. I don't think there's much else I can really do at this point other than get a new plastic strip.

 

[raynkar]

It's hard diagnosing by text isnt it lol.
I can only post this pic again. If you look at the screen strip you can see how far across mine comes. You can also see that it's so loose that it has slipped below the screen.
When fitting the passenger side cowl I start it the passenger side and make sure the tongue on the cowl positively clips into the rebate on the screen strip. Once the first bit is in place it's a bit like sealing one of those resealable sandwich bags, if the first bit is right then the rest clips into place properly. It's the join between the tongue and rebate that make he joint water tight, not the top of the cowl being close to the screen.

The screws at the front of the cowl don't need to be very tight as they go into little white plastic parts and not metal.



I've just had another idea, and it's a bit mental, but how much of a gap is there between the top of your windscreen and the top edge of the roof panel. There should be a gap about 1cm deep

 

[raynkar]

Do you have quite a big gap between screen and roof panel like in this pic?

 

[mondy zetecs]

'I've just had another idea, and it's a bit mental, but how much of a gap is there between the top of your windscreen and the top edge of the roof panel. There should be a gap about 1cm deep'

I will silicon around the whole windscreen next if mine still leaks

 

[raynkar]

'I've just had another idea, and it's a bit mental, but how much of a gap is there between the top of your windscreen and the top edge of the roof panel. There should be a gap about 1cm deep'
I will silicon around the whole windscreen next if mine still leaks

You'd regret doing it
The gap is the water channel to stop water flooding the screen when you brake

 

[mondy zetecs]

Probably won't be doing that then.

Will have to buy a waterproof car cover for rainy days.

 

[Communist]

Based on memory and the pictures I have there is a gap at the top of the windscreen. At a guess i'd say it's about half a cm or so.

 

[raynkar]

Probably won't be doing that then.
Will have to buy a waterproof car cover for rainy days.

I bought a waterproof cover for my mk3. The funny thing is that I did loads of research into which were the best ones only to find most of them aren't waterproof

It seems they keep dust off or a very very light shower, but not rain or snow

 

[oldbod]

Always worry that with a cover used outside the damage from the cover fretting against the car plus trapped damp will be worse than the weather damage - or are the newer materials better than that? Showing my age here...