Steamy windows

[Vic Young]

My 2003 TDI windows slowly steam up in cool conditions whether the air con is on or off (econ mode). (Only happens when driving; no condensation when parked). It doesn't matter whether the blower systen is on or off the car slowly but steadily steams up. The fans are normally always on at a medium setting. Normal fan use has little effect and only a quick blast from the boosted screen blower shifts it temporarily. Slightly opening the window removes it very quickly. The radiator is not losing water and there are no signs of leaking into the car. Any thoughts where this water vapour is coming from (or possibly not going to, as the moisture may arise from the passengers and simply not be vented from car). The speed and quantity of condensation does appear proportional to the number of people in the car. All suggestions welcome. Thanks

[shooey88]

condensation will be caused from water inside your car...
check all over the carpet for dampness.

even lift up the carpets slightly at each corner both passenger or drivers side and feel if they are wet underneath.

most probably be wet.

[Vic Young]

I've checked the carpets and found no evidence of dampness (without pulling them up). Everything seems bone dry with no hint of the mustiness you get when something is wet. A subtle leak is still a possibility though. Are there any areas in the Passat prone to leaking? From memory, there's no relationship between raining/car washing etc and this condensation (I'll need to check this more carefully though). I would expect condensation on windows in the morning from a leak. There is none. This condensation only appears with people in the car, when travelling. Thanks.

[shooey88]

the passats are prone to leaks. easy to slightly lift the carpet up in each area and slide your hand under

if it happens when raining then it would suggest water leak..but you say otherwise

if it happens when you have your aircon on...the aircon drain tube is prone to leak under the glove box in passanger footwell

is it just the front windscreen or all the windows as this would point u in a certain area.

for example if its just the front windscreen....you can check the plenum chamber under the bonnett where the battery is....it sumetimes fill with water there.

loads of suggestions for u...is the problem that severe and noticeable as abnormall then?

[dana4tdi]

I have noticed this in the past with cars with Climate control in.

Is the "drip" pipe for the air con blocked or restricted, could be a build up of condensate in the chiller unit?

Or another idea is that the system is constantly on re circ regardless of your re circ switch setting?

Or finally ask passengers to refrain from sweating and breathing, not very practicle, but is may solve it!!!!!!!

[Vic Young]

Thanks. The best description is that the symtoms would match constant recirculation even although this is switched off. All windows steam up progressively and evenly until it would be impossible to drive. The more people the faster it steams up. A blast of the blower cleans the front window for a short time or a slight opening of the window quickly clears the car and keeps it clear (and cold). I've left the air con off for a month as I too wondered about condensed water but this made no difference. The constant recirculation seems an excellent candidate for the symptoms. Is this a known fault and any suggestions on how to check this? (Multimeters etc all available).

[dana4tdi]

ON my A4 you can tell by listening to the airflow when you switch from re circ to external and back again, you can do this with the car still and the ignition on, as to how to fix it I can offer no advice..

[shooey88]

i disagree.....i will put money on it that you have water under your carpets.
its the most likely cause on all passats being common.

[shooey88]

if you have the window open and this clears the window screen....then having the recirc open is a similar thing...it creates a opening at the pollen filter for fresh air to come in.....so how do you explain that as a cause? it would only effect it on cold wintery days where it would cause maybe frost on the windscreen inside.

[Vic Young]

I've just checked the air con by switching the recirc on and off with the engine off (excellent idea.. thanks) and can hear a quite distinct change in the airflow. This suggests the recirc is working normally although this seemed an attractive idea.
At the present stage I'm ruling nothing out and will continue looking for leaks, checking if this corresponds with rain etc. I'll also have a look at the battery plenum (just read about it on this forum this morning) and probably remove the offending grommet.
So nothing is ruled out and all ideas are welcome. Someone will eventually prove to be right (I hope) and the glory will (deservedly) be their's. If only I knew who it was going to be now it would save a lot of grief. Thanks for all the help so far but keep the thoughts coming.

[Vic Young]

Had a look in the battery area. I thought I was on to a winner when I saw a crack in the plastic panel fitted round the wipers and across the car (not the one immediately above the pollen filter). This crack was directly above the pollen filter so I thought it might be getting wet. The filter was checked and although dirty was dry.

There was quite a lot of water retained around the outside of the base of the filter, the corresponding area on the driver's side and, I think, too much water in the battery base. This was all retained by dirt and quite a lot of sycamore seeds. It's quite possible that water is seeping in slowly somewhere. Any likelihood of this water being evaporated by the heat of the engine and drawn into the air intake via the pollen filter?
I think as a first step this plenum grommet under the battery has to go. Is this done from underneath the engine or does the battery come out or be lifted (seems quite a tight fit)?
The balance swings towards the leak theory but the race is not over yet so please keep the advice coming.

[Vic Young]

Just read Lex Luthor's excellent article on cleaning the battery area grommets so on my way, spanner in hand.

[shooey88]

you can get a long screwdriver and just reach the grommits to clear these drain tubes that are blocked with leaves etc.

the pollen filter will be most probably leaking water around the edges where it is sealed.....just lift up ur carpet under the glovebox and check if its wet on the passenger side.

[Vic Young]

I think it will be the 'poke with a screwdriver' approach.

I've passed the last hour or two trying to get the battery out. Lex Luther's article was very helpful however the wiper arms and plastic tray need to come off in addition and the wiper arm doesn't want to play. It looks like a two legged puller is called for. I've never had such difficulty either removing a wiper arm or a battery. Rude things were said about the designer of the battery area's behind and my right boot.

The rain started to pour down (did it in the drive) so called it a day after cleaning round the pollen filter area. Water was being held there by muck. I removed the filter but there was no signs of water entering the housing and the carpet appears dry. A leak here would match the symptoms though. Does the battery grommet have to be poked from below? I just love taking off the undertray and getting a facefull of dirt.

I couldn't see a second grommet under the brake servo as in the article. The whole area has been given a good flush with water (nothing leaked inside) to remove dirt. It's back to work tomorrow however I shall keep a careful record of when (if) it steams up and the weather at the time, check more thoroughly for leaks and resume investigation in a few days.

Many thanks. More thoughts and comments welcome.

[shooey88]

you can get to the holes with a long bendy pipe or screwdiver...without taking battery off etc u do it from above and dont need to jack the car up

have a go....you just need to wiggle around till u poke through the 2 holes in the plenum chamber

the carpets are really thick on the passat and i still say there will be water underneath them.

when the plenum chamber fills with water it can leak through the pollen filter seal or the drivers side E_box.

so this means you can have water entering the car either side....you wont be able to see it from the outside unless you see slight white powdery water marks.

[Vic Young]

Many thanks Shooey88.

I've had a good poke under the battery tray with a bent piece of welding wire (end rounded and smooth). The wire appeared to enter somewhere at times but I'm not 100% convinced that it was the grommet. I tried getting at it from the engine side and locating it by pouring water under the tray. The water poured down in a position corresponding to the back of the battery but I couldn't reach it. All I succeeeded in doing was getting a very black arm. This suggests that the grommet is draining but I think I'll take the battery out and make sure it's done correctly. It may be that the fault is cured as there was water trapped in the area around the pollen filter which has now been cleaned and is draining freely. If this is correct then steaming up should progressively reduce during this week.

Removing the battery does involve removing the wiper arm. A puller seems a bit of overkill for the job but it seems to be the way with the least potential for damage. Any tips on removing the wiper arm and the little tray underneath?

[kje]

Hi everyone,

Just joined to comment on this.

98 1.8t owned for 6 yrs, my only gripe is steamed windows. I have done EVERY thing mentioned on any forum. The carpets are dry so have discounted that. The only thing i have found is water (lots) on the back of the heat exchanger in the ducting along from the blower. Car static, turn on fan = window steams up! Will probably try bags of silica-gel in there.

I have almost stripped this car down trying to find the cause, no smells/obvious signs etc.. Airbag out, back in, fault light!!

PS. If you remove the big harness off the bulkhead the battery might come out without doing the wipers??

[Sam]

Is the "steam" slightly oily?

[Vic Young]

My steam is pure water with no trace of oil. Since ensuring the area around the pollen filter drains freely there has been no more 'steaming' this week but this is a little too soon to consider success. That needs a cold day with passengers and the windows to remain steam free .

I did try getting the battery out after moving the wiring bundle. I could probably just pull the battery out (with the plastic fascia bending) but it wouldn't have gone back without the likelihood of damaging the fascia. The wipers will have to come off. I'm giving it until the next wet cold spell to see if the problem still exists. Hopefully Shooey88's advice has done the trick. Keep up the good work Shooey88, it's much appreciated.

[shooey88]

respect vic young...dont give up as if you solve it fixing yourself, it such a rewarding feeling.
one of the enjoys of working in a motor trade.....the other joy is hearing good customer feedback..but unfortuntly working for a main dealer i never get the opportuntiy to hear it as dont have customer contact....why i like using this site :biglaugh:

[kje]

Is the "steam" slightly oily?

Hi,

No oily residue just pure water. Used to be over anything cold before I sealed the pollen filter housing with tonnes of silicone.

Now it's just the windows (when cold, below 8 degrees or so). Very, very annoying, spoils a nice car, will have to think very hard about another vw.

[davejcb]

I have tried the recirc button, only when in auto mode does it make a difference to the sound, not very much. I'm thinking my recirc / fresh "flap" is stuck in the recirc condition, anyone know where it is so i can wedge it in the Fresh position? - or poss fit an override switch???

Please help, i'm fed up of having to open the windows when its damn freezing

Cheers

Dave

W Reg Passat TDI (SE) 90BHP

[PeoplesMan]

This was probably covered and I didnt read the entire thread so sorry if it has been but on reading the user manual some time back I am certain it said to use ECON mode only to heat the car quickly as this will lead to the build up of steam on the inside of the windows as it is recirculating the air and if you use AUTO when the Climate Control is up to the preferred heat you wont experience this issue !?

Am I wrong ?

Have I duped info ?

Does my bum look big in this A8?

[davejcb]

i have tried econ, i have tried nothing showing, and i have tired auto. nothing works

[roborod1969]

My 2003 TDI windows slowly steam up in cool conditions whether the air con is on or off (econ mode). (Only happens when driving; no condensation when parked). It doesn't matter whether the blower systen is on or off the car slowly but steadily steams up. The fans are normally always on at a medium setting. Normal fan use has little effect and only a quick blast from the boosted screen blower shifts it temporarily. Slightly opening the window removes it very quickly. The radiator is not losing water and there are no signs of leaking into the car. Any thoughts where this water vapour is coming from (or possibly not going to, as the moisture may arise from the passengers and simply not be vented from car). The speed and quantity of condensation does appear proportional to the number of people in the car. All suggestions welcome. Thanks

check your near side footwells for damp carpets.

[davejcb]

My 2003 TDI windows slowly steam up in cool conditions whether the air con is on or off (econ mode). (Only happens when driving; no condensation when parked). It doesn't matter whether the blower systen is on or off the car slowly but steadily steams up. The fans are normally always on at a medium setting. Normal fan use has little effect and only a quick blast from the boosted screen blower shifts it temporarily. Slightly opening the window removes it very quickly. The radiator is not losing water and there are no signs of leaking into the car. Any thoughts where this water vapour is coming from (or possibly not going to, as the moisture may arise from the passengers and simply not be vented from car). The speed and quantity of condensation does appear proportional to the number of people in the car. All suggestions welcome. Thanks

No More Steamy windows, this was my solution, maybe worth checking to see what the flap under the pollen filter is doing, mine seemed to be stuck closed.
http://www.vwaudiforum.co.uk/forum/showthread.php?t=23018

[eko]

I had a similar problem on a 2003 Passat. Every time the outside temperature reached approximately 0 deg C the windows would steam up with the climate control in AUTO or ECON mode. The dealer found the fault with the motor which controls fins for the air flow direction behind the dash-board. After the new motor was fitted the problem went away.

[SKINNYSEAND]

How much did it cost to fit the new motor?

[eko]

It was about £600 in total. The motor was only about £100. To replace the motor you have to take out the dash.