Leaky VW Passat- any ideas?

[northwind]

My dad's asked me- since I'm supposed to be the practical one - why his car's full of water. It's a 98 Passat Estate Mk5 S model, 2 litre engine in it. Apparently it's occasionally had dampness around the front passenger seat well, but it's mainly in the rear passenger side, and it's quite a lot of water- couple of cm when I saw it but it's been higher from the looks of it. It seems to happen when it's parked rather than when driving so I doubt it's coming through the floor or bottom of the doors, so I think probably sunroof or somewhere else on the door? It might be two seperate issues though, or it might even be the same problem with water running into the front when driven, or possibly the other way round.

(I'm not ruling out the possibility that the front passenger seat thing is down to something leaking, shopping or a water bottle or somesuch)

I know a lot of cars have fampous weakspots like rust in sunroof surrounds, etc, does the Passat have any of these? The car's in overall solid condition as far as I can tell, it was MOTd fine 2 months ago and had work done on the rear brakes at a good dealer so I'm reasonably sure there's not a big hole in the floor.

Any help appreciated, cheers!

[dirtydog]

The normal culprit for these sorts of things is the sunroof. Used to have an espace which had a sunroof above the rear seats, it leaked a lot! The water used to drip down between the back of the front seat and rear seat and then run down into the passenger footwell where it would gather and build up to a cm or 2

our friends polo has the same problem, does the car have a rear wash wipe? i know on mondeos the pipe can split or come loose and then water leaks into the rear foot well.

Its unlikely to be rust related. I have a 98 passat and its as solid as a rock.

A bit iof research threw up these nuggets..

I had that problem but on drivers side. I methodically tracked the water back by seeing the waterstain marks. I turned out to be a seam on the wing which sealed by a perished rubber strip.
I solved it with transprent silicon rubber. This is sticky to apply even using a gun so mask off adjacent paintwork. The advantage was that if not required it could be easily pealed off! Just make sure you get the one that evolves acetic acid (see instructions) as the one that does not is not so rubbery.

And also see here

HTH

Gordon

Hi mate,

Again from the VW perspective, check for the rear wash/wipe pipe as on some VWs it can split somewhere near the rear passenger seat. I don't reckon its that though if there's a lot of water.

Sunroof? - Check the drain pipes are clear by blowing through with low(ish) pressure compressed air. If there is one, this could be a good candidate.

MAIN SUSPECT - Scuttle drains. In where the front wiper mechanism is, and most likely the Cabin/pollen filter. Take off the covers and remove the pollen filter. Check thoroughly for signs of any drain holes and give those a check.

Another possibility is the door seals. These have been known to suffer on VWs also after a number of years. Look for signs of damage both front and rear. You could also try some vaseline on them and see if the water lessens.


Good luck,

Garry

[northwind]

It seems like it's most likely to be the bulkhead drains or the pollen filter like some folks have said- I found an excellent walkthrough for that so I hope that's what it is, I can fix that myself! I know nothing about cars, other than that yours and his parked side by side looked like father and son!

Another thing to look at is the plastic membrane/sheet behind the door card. This is designed to keep any water that gets into the door out of the passenger compartment. Make sure the drain holes in the bottom of the door are clear and the plastic membrane is securely fastened.

If you still have a leak after discounting all the obvious places;
Door to body rubbers
Door membranes
Sunroof seal
Sunroof drains clear
Roof mounted aerial
Air conditioner drain blocked
Heater matrix leaking (will have anti-freeze in it)
Screenwash hose leaking
Windscreen surround

Sometimes the most effective way of tracing a leak is to chalk a line along all the likely routes for the water to enter by. Get someone to hose the car down while you look for the leak source, the chalk line will help to identify where the leak is.

Good luck.

Northy - have a look on the VAG forum...I seem to remember a common fauly with Audi's and passats - summat to do with blocked brain holes in the plenum chamber, and/or an air con fault...

linky...http://www.vwaudiforum.co.uk/forum/

EDIT - not sure its the same, but have a look at this thread...

http://www.vwaudiforum.co.uk/forum/s...ad.php?t=28966

[northwind]

Hee hee, you said vag.

Er, I mean, thanks!

its 99% going to be thos drains in the plenium chamber one under the battery and one just behind the brake servo. you can pull them out from underneath then you dont have to take the battery out (you might loose the radio) then you will have to take the pollen filter housing out because it messes up the seal. you have to take the wipers off and the screen trim of to get to it. use dum dum to reseal it. then you need to lift the carpet that side and dry it out,while the carpet is up check the control unit in the passenger footwell just to make sure there is no water in there (its in a black box). if you need to know anything else let me know ive done this so many times (i work for vw)

good luck