Passat water leaks - wet carpets

[Invictagunner]

Having had two Passats and much pain will pass on my experience.
Things to check for are:-
1) Blocked drain holes under battery shelf
2) Leaking pollen filter housing gasket
3) Leaking gasket under the ECU housing box

If wetness is on the passenger side primary suspects are 1) and 2)
If wetness is on the drivers side primary suspects are 1) and 3)

Any amount of dirt rotted leaves etc can cause a problem in these areas. Just because the drain holes are clear this does not mean there is no dirt problem. What happens is that dirt also accumulates around the channels to the side and back of the ECU and pollen filter housing. This causes a local build up of water before it drains away through the main holes - result is that it finds its way past the relatively poor pollen housing seal and or ECU housing seal. If you park near/under trees keep the whole of this area really clean on a regular basis.

If the passenger side gets wet - big trouble. The Convenience Control Module (CCM) is likely to be wet. This leads to troubles with the alarm, central lcoking, windows etc. Get this properly dried out and sorted before it get worse.

VW are aware of these problems and recognise the weakness of these seals. If 1) is clear and the problem is caused by 2) or 3) the dealer can fix the problem under warranty. There is an internal VW information note 443/06 sent to dealers in July 2006. Any car serviced after this time by a VW dealer should have been checked and if necessary the pollen housing seal replaced using new materials and the carpets and CCM checked. In the US there is a large court case aiming to sue VW for problems relating to inadequate body design, water leaks and in extreme cases brake failure on some models. In the UK there are some limited recalls as a result of the possible brake problems.(servo pipe rots through).

Finally to fix the problems properly you need to do the following:-
1) remove the windscreen wiper blades - can need a small pullar or two flat blade screw drives twisted from each side to create a lever effect. Once they have been removed once use some grease on the spindles to ease future removal.
2) Pull back the bonnet seal so that the plastic cover for the battery etc can be pulled away from the slot in the windscreen cowl.
3) Remove the two clips supporting the plastic windscreen cowl.
4) Gently lever out the cowl from a slot in the base of the windscreen by placing a protective cloth at the bottom of the screen and gently levering the cowl away from the screen by twisting a flat blade screwdriver. Start at the drivers side.
5) Manoeuvre the cowl from the car - you need to gently bend it a bit but be careful not to break it.
6) Now follow your nose to gain access to drain holes, pollen housing and ECU housing as necessary. There are many articles on the web if you need further info just search Google.

Good luck - I hope what I have found helps you - I have had to learn the hard way and still learning!!! I am sure there are other leaks through windows etc. but it is the under bonnet area that has always hurt me.

If the car is full of water the following may help - detail relates to a 2002 Passat estate.

I have found the following method is the easiest to get rid of the majority of the water:-

1) park the car with the front higher than the back - the more the better!
2) remove the rear seat by removing the plastic cover over the hinge - one screw covered by a plastic cap. Only need to do the side with water in it. Remove seat by driving out the hinge pins which are now free to move.
3) remove one screw holding side trim to the floor under the seat.
4) remove the small plastic caps covering the screws that hold the plastic covers for the seat runners. Remove the screws and runners.
5) It is now possible to manoeuvre the carpets from the side trim and raise so that the floor drain holes are visible.
6) Carefully remove one or both of the drain hole bungs and let out the water.
7) With the carpet supported by a couple of blocks of wood it is possible to squeeze water from the foam and generally extract as much water as possible. You can reach just past the rear heating ducts.
8) leave to dry for as long as required. Temporarily put the drain plugs back in if going out in the rain.
9) when the carpets are as dry as you can get them replace the bungs with a smear of vaseline or waxoil or similar to ensure a good seal. Replace if they are damaged.
10) Refit the carpet and put the trim and seats back in place. Not as good as taking everything out but at lease is easy to do without taking half the car to pieces.
11) In my experence the drivers front seems to dry in situ reasonably OK (car parked uphill!) with no great risk to other components. The passenger side (RHD) is different as a result of the CCM becoming wet as mentioned in the first part of the post.

Good luck

[djmx5]

INVICTAGUNNER...thanx so much for that detailed explanation of 'how to'.

Just got a tdi B3 and wanted to look at this very issue. Did so today and followed your advice.

On the passenger side bonnet hinge there was loads of damp muddy crud but the plenum chamber under the battery appears dry as was the pollen filter and housing.

I only got as far as removing the outer shield thingy, enough to see how to remove the wiper blades, un-do the two clips and figure out how to lever the wiring loom to one side and then slide out the remaining plastic shielding butted to the windscreen.

Definately a job for milder weather and longer nights.

Just one question, you refer to the ECU housing box. Is this the black unit located drivers side, in the same position as where the poolen filter is on the passenger side?

If so I see there is 4 or 5 bolts holding it together...is there anything else that I need to know about before I remove this to clean underneath?

Once again thanks very much mate.

D

[muddy]

Not too sure about unbolting the ECU box "to clean underneath".
If you haven't got a leak on that side I'd tend to leave it alone and not disturb the factory seal?

PS did you mean B3? What year is the car?

[djmx5]

If that's what the black box is then I have no intention of removing the ECU. My car 2005 tdi 130 estate

[David Horn]

I suffered problems caused by a leaky pollen filter last week. VW washed their hands of the problem and said that because the car is over 5 years old, they're not making a goodwill contribution. Dealer however offered a 15% discount on parts and labour.

Will be sending a nasty letter to VW head office tomorrow. They can whistle for me to buy another VAG car.

[muddy]

If that's what the black box is then I have no intention of removing the ECU. My car 2005 tdi 130 estate


"If so I see there is 4 or 5 bolts holding it together...is there anything else that I need to know about before I remove this to clean underneath?"

I took the above as meaning you might have a go at removing it .....

[Invictagunner]

The seal under the ECU housing can leak as the result of dirt building up. Water then builds up on the drivers side - front and rear (the lowest) footwells. Agree with anyone who says be careful in this area - do not attempt to disturb unless you have a leak from this area. Do not disconnect any of the wiring unless you are certain you know what you are doing.

The housing is held by three bolts - two accessible from outside the box and one only accessible by removing the 5 bolts holding the lid. It is quite safe to carefully remove the lid and then remove the remaining nut holding the housing. It is then possible to lift the housing a little without disturbing any of the wiring. This will enable any remaining gunge from the area to be removed and clean the top of the seal along with a smear of vaseline or similar.

If this solves the problem you are lucky - if not get the car to a dealer or independent expert who can fix without taking a risk.

[mawbs]

Many thanks information is spot on. I have an 03 1.9 TDI Passat which has suffered same ingress of water problem. Both rear passenger wells were wet! Problem area was drain holes under battery. Having removed rear seats and prised carpet up at rear , reluctant to remove front seats due to airbags and heated seats. Where exactly is the Convenience Control Unit and are there any cable runs beneath the passengers side foot well.

[Invictagunner]

On a RHD car the CCM is under the passenger footwell carpet in a recess in the floorpan. It is possible to gain limited access by just raising the carpet without removing the seat. If it has remained dry no problem. If it is wet then this normally spells trouble since the wiring and terminals corrode leading to problems with the alarm, door locking etc. In this case it may be best to get it properly checked out. Most independent auto electrics experts know this problem very well and can often fix much cheaper than a VW dealer. Good luck.

[burnleywhite]

Glad I found this thread. I have an 03 2l SE petrol. Over the last few months things have been going a tad iffy on the electrics front. Front N/S window stopped working (an horrendous grinding /screaming when I accidentally press the button so I assume summat has broken), then the rear N/S door stopped locking/unlocking on the fob, wont open every time now even when the handle is pulled inside the car (this has also happened on the O/S rear door too but only now and again, and when I lock the car sometimes the lights flash, sometimes they don't. Also it can take 2-3 presses of the fob to open all the doors (those that work) sometimes.

Pity because I love the car. It looks classy and is a pleasure to drive, and I have had it 3 years now with not a single penny spent outside servicing. Too good to be true probably.

[KieranM]

Glad I found this thread. I have an 03 2l SE petrol. Over the last few months things have been going a tad iffy on the electrics front. Front N/S window stopped working (an horrendous grinding /screaming when I accidentally press the button so I assume summat has broken), then the rear N/S door stopped locking/unlocking on the fob, wont open every time now even when the handle is pulled inside the car (this has also happened on the O/S rear door too but only now and again, and when I lock the car sometimes the lights flash, sometimes they don't. Also it can take 2-3 presses of the fob to open all the doors (those that work) sometimes.

Pity because I love the car. It looks classy and is a pleasure to drive, and I have had it 3 years now with not a single penny spent outside servicing. Too good to be true probably.


Your N/S window screaming sounds like a breaking/broken window regulator, mine was broken but by the time I owned the car the regulator and become tangled in the motor cog, and stripped it, paid £40 for the motor and a bit more for the regulator from GSF or Eurocar parts.

The rest I guess is CCM stuff.

[caldirun]

Good "How To", just like to add, remove the rubber valves in the plenum chamber, they are a waste of space, I left mine in the first time then suffered another flood, they are now history and contrary to suggestions they serve no purpose.

[burnleywhite]

Cheers gents. I thought that was what is wrong with the window, did start stripping it out in the summer but it was getting the better of me so I sacked it. Have to wait for the weather to improve/days get longer before I start having a look at the CCM, has to be done on the street so need to, hopefully, get it sorted first time.

[peterpaulogrady]

Having had two Passats and much pain will pass on my experience.
Things to check for are:-
1) Blocked drain holes under battery shelf
2) Leaking pollen filter housing gasket
3) Leaking gasket under the ECU housing box

If wetness is on the passenger side primary suspects are 1) and 2)
If wetness is on the drivers side primary suspects are 1) and 3)

Any amount of dirt rotted leaves etc can cause a problem in these areas. Just because the drain holes are clear this does not mean there is no dirt problem. What happens is that dirt also accumulates around the channels to the side and back of the ECU and pollen filter housing. This causes a local build up of water before it drains away through the main holes - result is that it finds its way past the relatively poor pollen housing seal and or ECU housing seal. If you park near/under trees keep the whole of this area really clean on a regular basis.

If the passenger side gets wet - big trouble. The Convenience Control Module (CCM) is likely to be wet. This leads to troubles with the alarm, central lcoking, windows etc. Get this properly dried out and sorted before it get worse.

VW are aware of these problems and recognise the weakness of these seals. If 1) is clear and the problem is caused by 2) or 3) the dealer can fix the problem under warranty. There is an internal VW information note 443/06 sent to dealers in July 2006. Any car serviced after this time by a VW dealer should have been checked and if necessary the pollen housing seal replaced using new materials and the carpets and CCM checked. In the US there is a large court case aiming to sue VW for problems relating to inadequate body design, water leaks and in extreme cases brake failure on some models. In the UK there are some limited recalls as a result of the possible brake problems.(servo pipe rots through).

Finally to fix the problems properly you need to do the following:-
1) remove the windscreen wiper blades - can need a small pullar or two flat blade screw drives twisted from each side to create a lever effect. Once they have been removed once use some grease on the spindles to ease future removal.
2) Pull back the bonnet seal so that the plastic cover for the battery etc can be pulled away from the slot in the windscreen cowl.
3) Remove the two clips supporting the plastic windscreen cowl.
4) Gently lever out the cowl from a slot in the base of the windscreen by placing a protective cloth at the bottom of the screen and gently levering the cowl away from the screen by twisting a flat blade screwdriver. Start at the drivers side.
5) Manoeuvre the cowl from the car - you need to gently bend it a bit but be careful not to break it.
6) Now follow your nose to gain access to drain holes, pollen housing and ECU housing as necessary. There are many articles on the web if you need further info just search Google.

Good luck - I hope what I have found helps you - I have had to learn the hard way and still learning!!! I am sure there are other leaks through windows etc. but it is the under bonnet area that has always hurt me.

If the car is full of water the following may help - detail relates to a 2002 Passat estate.

I have found the following method is the easiest to get rid of the majority of the water:-

1) park the car with the front higher than the back - the more the better!
2) remove the rear seat by removing the plastic cover over the hinge - one screw covered by a plastic cap. Only need to do the side with water in it. Remove seat by driving out the hinge pins which are now free to move.
3) remove one screw holding side trim to the floor under the seat.
4) remove the small plastic caps covering the screws that hold the plastic covers for the seat runners. Remove the screws and runners.
5) It is now possible to manoeuvre the carpets from the side trim and raise so that the floor drain holes are visible.
6) Carefully remove one or both of the drain hole bungs and let out the water.
7) With the carpet supported by a couple of blocks of wood it is possible to squeeze water from the foam and generally extract as much water as possible. You can reach just past the rear heating ducts.
8) leave to dry for as long as required. Temporarily put the drain plugs back in if going out in the rain.
9) when the carpets are as dry as you can get them replace the bungs with a smear of vaseline or waxoil or similar to ensure a good seal. Replace if they are damaged.
10) Refit the carpet and put the trim and seats back in place. Not as good as taking everything out but at lease is easy to do without taking half the car to pieces.
11) In my experence the drivers front seems to dry in situ reasonably OK (car parked uphill!) with no great risk to other components. The passenger side (RHD) is different as a result of the CCM becoming wet as mentioned in the first part of the post.

Good luckwet carpets usually mean you have lost the drive belt off your air conditioning.look under the car you shold be able to see the pulleys

[caldirun]

wet carpets usually mean you have lost the drive belt off your air conditioning.look under the car you shold be able to see the pulleys
OK, you have me beaten, where is the logic?

[peterpaulogrady]

i dont understand it myself but my brother inlaw had the wet floor behind the drivers seat and the air conditioning was faulty and it turned out that a drive belt some how came loose:beerchug:

[caldirun]

i dont understand it myself but my brother inlaw had the wet floor behind the drivers seat and the air conditioning was faulty and it turned out that a drive belt some how came loose:beerchug:
I once ate an ice cream on a very long run and had a sore foot 40 miles later, but I doubt they were connected in any way!

[yaman]

i dont understand it myself but my brother inlaw had the wet floor behind the drivers seat and the air conditioning was faulty and it turned out that a drive belt some how came loose:beerchug:

Never ever believe anything your in-laws tell you, your welfare is
not their concern. :D

Regards
Jim

[breweruk]

Thanks so much for this detailed information. I followed your instructions, parked the car on an incline, lifted the carpet and found that the rear foot areas were saturated. We then used 15 old towels to drain it and left the car with the doors open for the afternoon.

I did it without too much trouble. Just lifted the rear seat and pulled the carpet forward. I had to remove two black plastic covers on the front seat rails first. Then I propped the carpet up, mopped up the water and let it dry.

See pic below.

14330

While the car was drying I opened the bonnet and tried to clean out the well under the battery. That was flooded, too. I didn't remove the battery but just shoved some old towels down there and prodded them around with a wire coat hanger. That seemed to do the trick and the water went down and I noticed a steady drip under the car.

So far so good.

Then it rained and when it stopped I noticed drips in the foot well around the wires. So it seems that water is still getting in via the wires - on both sides. Does anyone know where the wires enter the car so I can attack it with sealant?

See pic below.

14331

Thanks in anticipation. And, once more, thanks for this brill forum and such helpful posts.

[Invictagunner]

I think you will find that the seal under the ECU housing is leaking. It then runs down the wires or any other channel it can find. Ideally you need to remove the battery and clear out the drain holes under the battery tray. If this area fills up with water it will find its way into the car somewhere or other. As suggested by one of the earlier replies it probably does no harm to discard the rubber skirts that VW put in the holes. You may also need to get the gasket under the ECU replaced. To do it properly it needs the new seal material now specified by VW. Dealers know all about this problem. If you ring a local dealer and ask for a quote to replace both the pollen filter housing seal and the ECU seal and then haggle, the job can cost about £170. This is not that bad considering the seals themselves are not cheap. If you try to do the job yourself you need to disconnect the main harness from the ECU - I decided this was a step to far without the dealer diagnostic kit to bring it back to life again. Looking back it was £170 well spent as (touch wood) the problem seems to have been solved - although it is still necessary to keep checking that the drain holes are clear.

[breweruk]

Thanks for that. I have printed off your advice and will take it to the local garage tomorrow.

[yaman]

the problem seems to have been solved - although it is still necessary to keep checking that the drain holes are clear.

Good luck with that.

Every time it rains, or the car gets washed, there's a fair chance of your car self-harming.

Better to remove the bungs sooner than later, believe me, you'll soon get weary of the
damp smell, lifting the battery in and out and paying for the damage.

Regards
Jim

[caldirun]

REMOVE the rubber duckbill valve under the battery tray, if you dont you will have the same situation next year (or later this year), dont try to seal the wires, if you do a really good job the water will build up and destroy your brake servo!!!

[Invictagunner]

Agree that you should remove the rubber skirts to help keep the main drain holes clear. However, VW has a further sting in the tail to ensure that you are 'got' even if the main drain holes are not blocked. The same type of muck, leaves, pine needles etc that block up the main drain holes also cause more local build ups of water that leak past the pollen filter gaskets and ECU gaskets before it can run down to the main drain holes. This is why it can also be necessary to sort out the seals and clean out all the dirt at the higher level as well as ensuring that the drain holes are clear.

[caldirun]

Agree that you should remove the rubber skirts to help keep the main drain holes clear. However, VW has a further sting in the tail to ensure that you are 'got' even if the main drain holes are not blocked. The same type of muck, leaves, pine needles etc that block up the main drain holes also cause more local build ups of water that leak past the pollen filter gaskets and ECU gaskets before it can run down to the main drain holes. This is why it can also be necessary to sort out the seals and clean out all the dirt at the higher level as well as ensuring that the drain holes are clear.
I must agree, but don't buy VAGs rubbish seals, use silicone sealant and no worry re unplugging the ECU, it wont need re-programing. Only problem could be the screen lower plastic trim, this may split as you pull it off, just buy a new one.

[akhlaq768]

I have a 2006 Passat and noticed the water on the driver foot well, as the battery is located on the passenger side how will this affect the driver side well?

[caldirun]

The water builds up and when you go around a corner it flows down the heating intake duct, then it can go into all the footwells front/back/left or right. Battery will lift out without disturbing the plastic strip around the wiper arms, don't just unblock the valves, REMOVE them or will occur again.

[akhlaq768]

Does anyone have picture of what I am suppose to be looking for under the battery for a b6 2006 model

[Eddie4]

Over the past few weeks I have been trying to rectify the water leak into the passenger footwell. After a lot of patience I have identified that the water is coming from the inner skin at the bottom of the A pillar. See photo.
35900
The water accumulates and is a couple of centimetres deep by the time it leaks through the holes that the wiring connecter frame clips into.
Any ideas as to how the water is getting in there, and/or how I can drain?

[caldirun]

REMOVE the bungs, did I say remove the bungs? have you?

[Eddie4]

REMOVE the bungs, did I say remove the bungs? have you?

Couldn't see any bungs. Removed nearest bungs to the a-pillar area under the car and no water came out.

[caldirun]

The bungs are under the battery in the plenum chamber, also replace the cabin filter housing seal, search on this site for instructions on how to do!

[Eddie4]

Oh yes I have done all of that. Fixed the cabin filter seal etc. If u look at the photo i posted the water is accumulating in the skin of the chasis and bleeding through near the floor. This seems to be different ingress point to the typical cabin filter seal. I don't have a sunroof either (which potentially could have been the cause).

[Gazwould]

Don't know if applicable but the inner doors brose metal panel seals perish in the lower half .

They all need resealing regardless .

[fleamoo]

Don't have my car with me to check, but is there a blanking plug on the passenger side of the car that corresponds with the bonnet release cable grommet on the driver's side? I say that because I cured a very similar looking leak on the driver's side of mine by replacing that grommet.

[Jimmy2007]

Hi, sorry to resurrect an old thread, but here is my problem.
I found water pooling under driver side front and back.
I always kept plenum chamber extremely clean and got rod of grommets years ago.
When i flush water on the windscreen it goes down the hole under servo and battery without obstruction.
I replaced the ecu seal and sealed bonnet release cable.
Got to say, found a lot of rubbish behind ecu case which was not visible.
I dried the car thoroughly.
Now, whilst replacing front driver seat, i lifted the carpet and found it a bit damp.
Passenger side is bone dry.
Tested all other water ingress points and all is good.
Could it be the cabin filter seal which i haven't fixed yet, even though is on the driver side only?
Thanks

[caldirun]

Checked the door seals?

[Jimmy2007]

Yes, hosed the doors for 15 minutes and the little water that goes in the door from the glass seal, goes out from the bottom.
Carpet was dry on door sides even when i found gallons of water, so i don't think there's a problem with the doors.
Or should i test them in another way?
Thanks

[fleamoo]

Try parking with the driver's side up on the pavement, then hose the doors again. This has made door leaks more obvious in my experience. Feel for any moisture just under the bottom of the door cards.

[VAG-Abound]

Sunroof?

[Jimmy2007]

Thanks for all your input.
Sunroof had been tested, all good.
Today we had a lot of rain in 10 minutes, went out and lo and behold both door seals are leaking in the gap between plastic trim and rubber.
So, next task is to seal them.
Somehow when i hosed them they didn't leak.
Mystery of the the Passat.
One question: do i use the same butyl sealant suggested for pollen filter, or is there a different product?
Thanks guys, i'm seeing an end to this finally.

[fleamoo]

Sorry about delayed reply. If you haven't already done the repair, I found butyl rubber goo sold in cartridges as gutter sealant works well. Remove door card. Notice how the window regulator panel bolts to the door. You don't have to separate the window regulator panel from the door, just smear sealant over the joint where the two meet. You only have to seal the lower half of the door because that's where the water gets in. The goo is messy, black, non-setting stuff but it's covered up when you put the door card back on. Bit of a bodge, but it seems to last well and is a useful timesaver when you've got two or more doors to do!