Hi all, I've got a water ingress from the front passenger footwell :-( Today morning, when I switched the heaters on, water was pouring through from under the dash, could the drain holes by the pollen filter be blocked, causing water to seep in through the heater matrix??

could be from the pollen filter housing (on the left hand side of the footwell as you are sat/looking into the car) or could be from the matrix or the matrix drain (more likely) which is on the right hand side of the footwell just to the left of the central tunnel. The matrix going on one of these is not common.

Where exactly is the water coming from, left or right hand side? Will help me direct you further

Thanks for the reply :-) Today I cleaned out the pollen filter and the drain hole on the right hand side of the pollen filter, however water is still coming through :-( On the passenger side, there's a cover that covers the heater matrix, water is coming in through there..

the heater matrix is built into the airbox assembly, so its coming into the car on the righthand side of the passenger side footwell by the central tunnel?

there is a drain which goes out at 90degrees to the airbox setup and that allows the water from the aircon system that collects in the airbox to drain, it could be the rubber seal between this drain pipe and the bulkhead thats no longer fitting properly and allowing water to come back into the car down the bulkhead. You need to pull the carpet away to check at the bulkhead.

Water can also get into the airbox system and the car by the pollen filter housing, if the drain to the side is blocked, and the housing in the scuttle area isnt seated properly and sealed then it can get in here. Double check the housing for the filter is sealed in.

The water is coming in from the central and left hand side on the front passenger footwell, from the heater matrix. The scuttle panel is secured properly and the pollen filter drain hole is clear, and the pollen filter is sealed on, as the mechanic applied extra sealant when securing the pollen filter housing in place. Any ideas?

the matrix is on the right hand side of the the passenger footwell, it sits literally above the central tunnel inside the airbox.

if its not coming from under the filter housing (or through the filter if the scuttle is not secure) then it has to be from either a grommit that is not in place in the scuttle area (there are several, one being behind the pollen filter housing, you cant see this but you can feel it) or the aircon drain or the matrix itself.

 

To establish if its the matrix or not is simple...

 

firstly is it water or coolant? you don't mention this, but its easier to pinpoint knowing this.

 

if its water (doesnt smell or feel slimey) then its the drain or a leak

if its coolant (you will smell this) and it feels different plus will be warm if the car has been run, and the car will steam up loads inside then its the matrix.

 

if its not coolant based, i recon its the drain which will normally allow water to pool under the car after a journey with the aircon on, basically if you get no puddles underneath its not getting out through the bulkhead grommit.

 

never heard of a matrix going on one of these, so i doubt thats it.

if it is...god help you..

Lol im pretty sure it's water coming through as it only happens when it rains, and it has no smell and doesn't feel slimy.

Sorry, I've made a mistake, the water is coming through the heater fan on the left hand side of the front passenger footwell. Sorry for the mix up :-( Any ideas?? Thanks in advance

lol, if its coming in through the fan, it is coming in through the pollen filter area. Though to be sure have you checked the drain grommit i mentioned in the bulkhead?

 

there is a shield that can fit over the pollen filter at the front to deflect water, if the fitler feels wet its coming off the scuttle, then going through the filter into the fan.

 

has your mechanic removed the housing? and then sealed it in properly 100% as its a right pain to remove and you cant gtee the seal if he only fits silicone around it in situ. If he only sealed it in without removing it could be from there.

It has 2 plastic nuts holding it with an OE seal from factory iirc.

I haven't checked the grommit in the bulkhead, where exactly is it??

The mechanic did remove the pollen filter housing, and applied extra sealant underneath the housing.

right behind the filter housing.

 

thing is, if water is getting in through the airbox (the fan sits in part of the airbox housing) then it is coming in through the pollen filter/under the filter rather than through the grommit.

If you have water coming from behind the dash, and going down the bulkhead, then its probably the grommit.

Interesting that the issues have started since someone has applied a third-party sealant to the pollen filter housing.

 

I've had my housing out a couple of times, once to get into the scuttle panel area to really clean it out, and again to help me route some cables for an ICE install.

 

Both times I have just removed the housing, and then just been careful to clean the bottom of the housing and the metal panel it bolts to, to make sure that the sealing area is totally clean and free from debris.

 

It may well be that the application of a load of silicone has actually created the problem and made it worse?

 

I'd remove it again, clean off ALL the silicone and bolt it down clean.

 

HTH

Thanks for the replies guys :-) The issue started before the pollen filter was changed and the area was cleaned. The water is definitely coming from the heater fan, not the bulkhead, as I've seen water dripping from the heater fan. I shall tell my mechanic to remove the sealant and fully clean the pollen filter area again. I'm just hoping it is coming from the pollen filter, as I'm sick of soggy carpets :-( Anything else it could be??

realistically its from the fact he has moved the filter housing. Out of interest why did he take the filter housing out and not just change the filter. I suspect an incomplete seal of silicone has caused the issue. Which goes straight into the airbox feed and down into the fan. Not ideal and means your carpets will probably be proper wet (not least the sound deadening underneath) you might wanna try a fan heater in the car for a weekend or so (or removing it all and drying if you can as wet carpets at this time of year equals lots of condensation and fogging up.

He removed the filter housing to apply extra sealant, but as you said the sealant probably hasn't been applied properly. I had a look through the scuttle panel gaps today, (as i couldnt take the damn scuttle panel off) into the pollen filter area and there was water around the bottom of the housing, so tomorrow I'm back to the garage to take the housing off, and apply sealant properly. Any advice how much sealant to apply?? Also had a look under the carpet on the front passenger footwell, the sound deadening is completely soaked :-(

soaked sound deadening means ideally carpet up and deadening out, as it can go mouldy apart from anything else and smell. Not least you dont want anything rusting (not that it wil quickly) but still.

 

without sounding daft, as much as is needed to make a good seal, generous beading all the way round would be how i would apply it.

Okay thanks for the help and advice, will be going garage tomorrow and update :-)

No worries.

 

If you're gonna strip and re-apply the sealant, it might be worth asking your mechanic exactly what type of sealant he used?

 

There are a myriad of different types of sealant on the market all for different kinds of jobs. Some of them are designed to be squashed quite thin before they cure properly, others will cure well in a thick-ish bead.

 

Some cure quite hard, others cure but retain flexibility.

 

If you have a sealant that isn't designed for the job you use it for, then it's not gonna work!

Okay cheers, would you know the correct type of sealant to use?

Couldn't go to the garage today, however I took out the glovebox today, there's water droplets in the heater motor and next to the heater motor, theres a black box, and under that it's wet

Update today;

Took the passenger side scuttle panel off today, and noticed its missing a type of scoop underneath it, which I'm guessing directs the water away into the drain hole? New one ordered in for tomorrow, hopefully this was the issue!

This is what mine looked like before I sealed up the grommet/hole with a wire passing through it:

 

 

Overview:

 

and sealed:

Mines doesn't have a grommit there :-/

Does it just have a girt big hole?  All water run-off from that side of the windcreen passes over that location.

 

Some have a grommet on the other side of the pollen filter...

I've had a lot of problems with excessive condensation of the inside of the front and rear windcreens lately and knew there was water getting in somewhere. I got up early one morning after an evening of rain and checked the scuttle area, the scuttle itself was relatively clear but whereas the drivers side scuttle was clear, This gave me an indication that the water was most likely getting in around there somewhere. the passenger side was still quite damp with small pools of water still around the drain hole.

 

Having seen mbames post in the past, I sealed up the grommet as pictured above. I then checked the drain itself by pouring some hot water down it, although the water was getting through it was clearly not working as effectively as the drivers side one in comparison. The drains exit just behind the front wheel arch, as such if you remove the lower part of the rear of the arch liner (just undo the bottom few torx screws and move the lower part to one side, no need to remove the whole liner) you can gain access to the exit area.

 

I found that my passengers side drain exit was absolutely jammed up solid with leaves, mud and other cack, literally pulled three or four handfuls of the stuff out before giving it a hoover. Did the drivers side too, although there was next to nothing in comparison. Tried pouring water down the drains again and much better.

 

Three or four days on now and it appears to have worked a charm, Ive been up at 5:30am all week at sub 5C and haven't had slightest bit of water on the inside of the screens. Previously even the slightest bit of rain would cause the screens to fog on the inside and the rear screen would get so wet that it would never really clear now matter how long/hot the air con ran for..

Update today;

Fitted new scuttle panel, going to wet vac as much water as possible tomorrow and then hopefully there'll be no more leaks..pray for me!:-( lol