Volkswagen Passat (2001 - 2005) - 04 1.9 water under drivers seat

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Fri 27 Nov 2009 23:16
04 1.9 water under drivers seat - jk69
vw passat 2004 tdi saloon
Water under the drivers seat, carpets all wet through, where is water coming from, any ideas?
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Sat 28 Nov 2009 08:33
04 1.9 water under drivers seat - the_bandit
check pollen filter housing. has it been replaced recently? if so probably cracked or poorly re-fit.
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Sat 28 Nov 2009 09:57
04 1.9 water under drivers seat - Peter D
The pollen filter tends to let water into the passenger foot well. It's time the remove the scuttle form in front of the windscreen and check for debris behind and around the Engine electronics box that is to the left of the brake servo. Also check for water being retained in the Plenum chamber due to the two drain plugs being block up. Remove the Lid off the box and check it is dry. There is a seal between the box and the bulkhead. However a leak here tends to drip on your feet. Check water is not entering from behind the door card. There was a case on here not too long ago where the leak was traced to a failure of the bonded windscreen. Regards Peter
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Sat 28 Nov 2009 10:27
04 1.9 water under drivers seat - jk69
many thanks for your suggestions, will investigate these and report back!
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Sat 28 Nov 2009 11:01
04 1.9 water under drivers seat - 659FBE
This has to be about the worst piece of automotive design around - and VAG as usual are not honouring their moral obligation to put right the extensive damage this causes and modify the design.

It's usually the LHS of the car which gets wet as the pollen filter housing seal disintegrates and lets the water into the car, more especially if the plenum chamber drains are blocked (VAG put stupid "duck bill" plugs in them which block up with rotting leaves). Take them out.

A leak on the RHS is more interesting and I came across this after a dealer had changed the cambelt on a friend's car. To do this, the front of the car has to be pulled forwards about 4" and amongst lots of other things, the bonnet lock cable has to be disconnected. There's actually a coupler in the cable to facilitate this - if you know where it is.

This dear dealer didn't bother, yanked the front forwards and tore the bellows-sealed grommet out of the bulkhead causing a massive and expensive leak. Of course, all knowledge denied...

Moral: find a good, interested, established self-employed independent to do your work. These are good cars (the 4 cyl diesels, anyway) if you address their weaknesses and don't mess them up.

659.
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Sat 28 Nov 2009 19:43
04 1.9 water under drivers seat - Street Mech
The drainage hole is located under the battery tray, you need to remove the battery and the tray to find it.

Pete. (having a De cha vu moment)
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Sat 28 Nov 2009 19:50
04 1.9 water under drivers seat - 659FBE
There's another one under the brake servo - with a pipe going through the "slotted bung". This needs to come out too.

A blockage here results in the servo case being submerged as it sits in a depression in the plenum. It eventually rusts through and water enters the servo internals. As well as losing brake assist - which makes a heavy vehicle like this unstoppable by a mortal - the water ends up in the engine intake (petrol) which hydraulics the engine, or in the engine crankcase (diesel) via the vac pump, which mixes water with the oil and wrecks the engine.

Well done VAG - with a bit more thought you could have made the front wings fall off as well.

659.
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Sun 29 Nov 2009 12:43
04 1.9 water under drivers seat - dieselnut
Even worse, as I found out one frosty morning a few years ago.
If the water gets into the brake servo & freezes, you loose all your brakes completely, except of course your handbrake.
But it comes as a bit of a shock as you roll down your steep drive onto a busy main road & find you have no brakes.
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Fri 4 Dec 2009 17:53
04 1.9 water under drivers seat - 659FBE
Ah - so they did find a way of getting the front wings off. Brilliant.

659.
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Tue 22 Dec 2009 18:06
04 1.9 water under drivers seat - retiredray
Mine froze a few days ago and there is now water in the oil in the sump. How much water can the oil emulsify before it damages the engine and turbo? I have stopped using the car but don't know the extend of the damage if any.
SQ

Edited by Dynamic Dave on 22/12/2009 at 18:57

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Fri 4 Dec 2009 17:49
04 1.9 water under drivers seat - jk69
many thanks to everyone for your responses it has been very insightful and helpful, indeed the plenum chamber was full of water, and I have drained it, now I know where to look for the drain holes and bungs hopefully I can prevent it from happening all the time
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Sat 4 Dec 2010 19:40
04 1.9 water under drivers seat - topper3

I've had a similar problem with my 02 Passat Estate 1.9 TDI SE. I only found out when after a couple of days of sub zero temperatures, the brakes pretty much froze up on me. When I opened the bonnet I found that the servo was sat in a block of ice. Having defrosted and drained the water (after clearing the blockages of course) everything seemed to work normally again. Next frosty morning however, the same problem occured, this time thankfully while I was testing it on the drive. I concluded that water must have entered the servo and then frozen. Again I warmed the servo (with my wife's treseme hair dryer!!) and everything worked normally again.

My concern is, will the servo continue to hold water now that its no longer submerged, or should the problem now fix itself?

Anybody in the know?

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Sun 5 Dec 2010 15:53
04 1.9 water under drivers seat - Peter D

I suspect the water was entering via the seal under the Electronics box or even the grommet for the bonnet release cable. Regards Peter

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