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Audity
18-11-2009, 10:20 AM
Hi,

Excuse the length of this one.

Have read various posts/threads where the problem is that the windscreen is not demisting.
This one is slightly different.
The car is kept under cover overnight and when first entering the car the interior is nice and clear.
Fairly quickly the interior glass mists up but once the demist switch is pressed the blower blasts out and the windows clear.
Within a few miles, and unfortunately this is random, the side and rear windows show signs that they are trying to mist up again.
The next bit is the annoying bit.
Once I park the car up and leave it the windscreen becomes, fairly quickly, misted up.
This happened this morning within an hour of leaving it.
I went back out to it and I cracked open both front door windows and left it.
In no time at all the inside cleared and remains clear whilst the windows are slightly open.

The owners manual suggests that when the recirculating mode is employed you do run the risk of misting up the windows.
I did find,by accident whilst changing the cabin filter, the flaps were closed as if in recirculating mode whilst the engine was off, yet I have never pressed that button on the dash - its never in that mode.
On further examination the flaps do indeed work, but whether as they should is another question.

After all that the big question is - What is causing it to mist up ?

Any pointers would be more than welcome.

PS: If its of any importance the digtal temps are always set at 18C and even at that the air is warm - only gets cold when set to LO.

Alan02
18-11-2009, 10:58 AM
I would set climate temp to about 22`c,with air con switched `on` and try setting to `Auto` or set vents to windscreen.Ive noticed my car mists up easily if air con is `off`.You dont have water ingress into the cabin?check carpets in morning as any moisture in car will go to windows on warming up.

Audity
18-11-2009, 11:20 AM
I would set climate temp to about 22`c,with air con switched `on` and try setting to `Auto` or set vents to windscreen.Ive noticed my car mists up easily if air con is `off`.You dont have water ingress into the cabin?check carpets in morning as any moisture in car will go to windows on warming up.

Hi,

Thanks for the reply.
That was one of the first things that sprang to mind - water getting in somewhere.
The carpets all feel dry and there appears to be no water sitting around the battery/cabin filter areas which I believe can cause problems with water ingress due to blocked drainage.
I really dont want to even consider there may be a leak in the cooling system at/around the heater matrix allowing hot water in as you`re driving - I do think the symptoms would be a lot worse, as I`ve experienced once or twice before.
As we speak, car still sitting with windows cracked open - beautifully clear!!!.
Going to try shutting them again and see what happens.

kite
18-11-2009, 11:27 AM
I would run the car for a couple of days with heating as hot as you can stand to dry thr inside of the car.
Does the re-circ flap move as it should, open for fresh air closed for re-circ ?

Audity
18-11-2009, 12:01 PM
I would run the car for a couple of days with heating as hot as you can stand to dry thr inside of the car.
Does the re-circ flap move as it should, open for fresh air closed for re-circ ?

Hi,

We did a we test when I had the cabin filter out the other day.
While observing the flaps various combinations of buttons were pushed on the dash to observe what the flaps did.
Pressing the OFF button closed the flaps.
Switching it back on opened the flaps.
Pressing the recirculation button closed the flaps which reopened when pressed again.

I very rarely, if at all, actually use either of the Off ,Econ, Recirculation or Auto buttons yet I found the recirculation flaps closed when I replaced the filter.
Under what circumstances would they close themselves?

I tend to have the air directed to the screen all the time and adjust the blower level as required with setting at 18C as I dont like it too hot!!!.

kite
18-11-2009, 12:04 PM
I would run it 18C in auto, as you like this temp and see if it still mists up.
"AUTO" will run the aircon and de-humidify the incoming air.
The system runs in "AUTO" or "ECON", you must use one of them ???

Audity
18-11-2009, 12:15 PM
I would run it 18C in auto, as you like this temp and see if it still mists up.
"AUTO" will run the aircon and de-humidify the incoming air.
The system runs in "AUTO" or "ECON", you must use one of them ???

Hi,

You see.... that something they dont tell you in the book, that you MUST use one or t`other (or at least I haven`t come across it).
Excuse my ignorance with the air-con controls.
So what is the system doing with neither the "AUTO" or "ECON" deployed.

kite
18-11-2009, 12:19 PM
Not working.....
"ECON" is normal car heater/ cooler.
"AUTO" is aircon os as some say climate control, the heater works out where the air goes and at what temp.
How do you run the system with both econ and auto off ?

Audity
18-11-2009, 12:34 PM
Not working.....
"ECON" is normal car heater/ cooler.
"AUTO" is aircon os as some say climate control, the heater works out where the air goes and at what temp.
How do you run the system with both econ and auto off ?

At the moment, the blower level is set to 3,4 or 5 bars on the display depending on what sort of blast is required.
The temps are set to 18C both sides.
The air is directed towards the windscreen via the relevant switch.
Thats it.
No "AUTO" selected, no "ECON"selected, no "RECIRC" selected - it just blows air out to where I want it to go whether it be up. down sideways etc.

Am I just using the system as a bog standard heater or shouldnt I be able to do that ?

Cheers.

kite
18-11-2009, 12:37 PM
But I bet the econ button is lit...

Audity
18-11-2009, 12:48 PM
But I bet the econ button is lit...

How much ?

Joking apart, I quickly ran out to check but I knew the answer anyway - just wanted to make sure.

The only lights that are lit up are the bars showing the level of "blow" ,the temps and the light on the switch directing the air toward the windscreen - and the blower is blowing!!

All the other lights are off but do work when selected but I rarely do select them.

JohnyIre
18-11-2009, 12:50 PM
How much ?

Joking apart, I quickly ran out to check but I knew the answer anyway - just wanted to make sure.

The only lights that are lit up are the bars showing the level of "blow" ,the temps and the light on the switch directing the air toward the windscreen - and the blower is blowing!!

All the other lights are off but do work when selected but I rarely do select them.
I often have it the same as you. If I hit ECON, to turn the air con compressor off, the car tends to mist up fairly quickly. Turning ECON off and it demists.

kite
18-11-2009, 12:52 PM
How much ?

Joking apart, I quickly ran out to check but I knew the answer anyway - just wanted to make sure.

The only lights that are lit up are the bars showing the level of "blow" ,the temps and the light on the switch directing the air toward the windscreen - and the blower is blowing!!

All the other lights are off but do work when selected but I rarely do select them.

Damn, I owe you a beer, Try running the system with the Auto on for a couple of days and see if the misting stops, might be the car is a little damp.

Audity
18-11-2009, 01:05 PM
Damn, I owe you a beer, Try running the system with the Auto on for a couple of days and see if the misting stops, might be the car is a little damp.

Thats what I`ll try - it may be just a little damp but its annoying.
As far as ther beer goes....that`ll be lovely:beerchug:

kite
18-11-2009, 01:08 PM
have 2 beers on me.....:beerchug::beerchug:

Audity
18-11-2009, 01:43 PM
have 2 beers on me.....:beerchug::beerchug:

Even better :alcoholic- unfortunately I`ll need an invoice address :biglaugh:

toff
18-11-2009, 04:26 PM
I might have the wrong end of the stick..

But if neither the ECON or AUTO lights are on... that means the air conditioning is on (i.e. the compressor, evaporator etc are operational) but it's not in temperature regulating mode (because you have pressed the the air-flow +/- buttons or directed air to a specific area using the buttons).

Simply pressing the AUTO button will revert the a/c to full temperature & humidity regulating mode (it will attempt to hold the temp you have selected regardless of changes to the temperature outside).
If you press the AUTO button, then press the ECON button, it will do the same but without the benefit of the humidity evaporator and it won't go colder than the ambient temperature.

The main cause of a car persistently steaming up this time of year is hot air being blown onto damp carpets. This only usually happens in ECON mode (and briefly when the full a/c is on).

When the re-circ flap is closed (i.e. air is not being taken from outside) the air is sucked-up from the passenger footwell. If you don't have passengers when you are experiencing the steaming-up, you may want to check for dampness in the passenger footwell - your plenum chamber (where the battery lives) may be getting full of water!

Just a few thoughts there.. may be wrong though.
Al.

Alan02
18-11-2009, 04:57 PM
As mentioned,`Air Con` ON`...( No ECON .button illuminated)with `AUTO` illuminated,and temp set as required......OR .....as above with vent directed to Screen,this will turn `OFF` the AUTO lamps.Blower speeds will still be managed by C.C. Seemples.

Audity
18-11-2009, 05:47 PM
I might have the wrong end of the stick..

But if neither the ECON or AUTO lights are on... that means the air conditioning is on (i.e. the compressor, evaporator etc are operational) but it's not in temperature regulating mode (because you have pressed the the air-flow +/- buttons or directed air to a specific area using the buttons).

Simply pressing the AUTO button will revert the a/c to full temperature & humidity regulating mode (it will attempt to hold the temp you have selected regardless of changes to the temperature outside).
If you press the AUTO button, then press the ECON button, it will do the same but without the benefit of the humidity evaporator and it won't go colder than the ambient temperature.

The main cause of a car persistently steaming up this time of year is hot air being blown onto damp carpets. This only usually happens in ECON mode (and briefly when the full a/c is on).

When the re-circ flap is closed (i.e. air is not being taken from outside) the air is sucked-up from the passenger footwell. If you don't have passengers when you are experiencing the steaming-up, you may want to check for dampness in the passenger footwell - your plenum chamber (where the battery lives) may be getting full of water!

Just a few thoughts there.. may be wrong though.
Al.

Hi,
Thanks for the input.
I dont regularly have passengers - 5 days a week its only me in the car.
I have checked, not only the passenger footwell but all 4 and am getting nothing to make me think there is water there.
I agree with you totally with regards to hot air and damp carpets.
The whole issue makes me think there is moisture somewhere in the car that is not getting out.
Saying that I got in the car this afternoon and it was as clear as a bell and remained so for the 5 mile journey home.
I appreciate the pointers you have suggested and will have another closer look at the plenum and footwells incase there is something I`m missing.

Cheers.

Audity
18-11-2009, 05:51 PM
I often have it the same as you. If I hit ECON, to turn the air con compressor off, the car tends to mist up fairly quickly. Turning ECON off and it demists.

Glad Im not alone.
Strange one though, especially when its the only car in the carpark thats all misted up.
Its always been a bugbear of mine, cars misting up.
Don`t enjoy driving in damp weather due to this as you dont feel you have complete vision around the vehicle.

Alan02
19-11-2009, 11:28 AM
Next thing is check that the extraction air vents in the boot of the car.They have a rubber flap over them generally,and they vent the air to outside,so stopping the car misting etc.You will have to remove the liner covers to inspect.

Audity
19-11-2009, 11:45 AM
Next thing is check that the extraction air vents in the boot of the car.They have a rubber flap over them generally,and they vent the air to outside,so stopping the car misting etc.You will have to remove the liner covers to inspect.

Hi,

Does that go for the avant too ?
If so that`ll be next then.
What should I expect to find if alls as it should be.

Alan02
19-11-2009, 05:53 PM
Yes,the Avant should have small vents either side of boot area behind trims.It allows for air flow into and out of cabin.Have a look incase something is blocking them? Worth a look,as it will be just like having the `RECIRC` button on all the time = Misting Up!

phil2209
20-11-2009, 01:43 PM
Glad I am not the only one who gets confused with the whole ECON thing. The manual says you can turn it off, however I have only just managed to do that today (don't ask me how).

I had an A4 B5 (1997) and the heating controls were much easier to work out... however I have only had this 54 plate car since Wednesday!

Audity
20-11-2009, 06:51 PM
Glad I am not the only one who gets confused with the whole ECON thing. The manual says you can turn it off, however I have only just managed to do that today (don't ask me how).

I had an A4 B5 (1997) and the heating controls were much easier to work out... however I have only had this 54 plate car since Wednesday!

Actually, I quite agree with you.
I too had an A4 B5 and the heater/aircon controls seemed a whole load simpler - and it worked fine.
I find it odd that, from what Im led to believe, the climate control in the B6 is best left on AUTO which to me means its basically ON all the time.
And if you want to switch it OFF via the OFF, ECON or RECIRC buttons you run the risk of misting the place up.
Can the system not be used as a conventional heater with the added luxury of Aircon if required ie hot weather.
And another thing - how can you maintain a nice flow of fresh air from outside without having the aircon ON as I understand the RECIRC flaps which allow outside air to enter the vehicle close when you switch the Aircon off.

phil2209
20-11-2009, 07:47 PM
Sometimes I think they change things for changes sake!

All the other cars I have had always had the same sort of control. Hot, cold, passanger, driver, air con, on, off - simples!

I may grow to love it and never turn back. However I also said that about bovril and haven't eaten that since 1992 :p

Alan02
21-11-2009, 02:15 PM
Actually, I quite agree with you.
I too had an A4 B5 and the heater/aircon controls seemed a whole load simpler - and it worked fine.
I find it odd that, from what Im led to believe, the climate control in the B6 is best left on AUTO which to me means its basically ON all the time.
And if you want to switch it OFF via the OFF, ECON or RECIRC buttons you run the risk of misting the place up.
Can the system not be used as a conventional heater with the added luxury of Aircon if required ie hot weather.
And another thing - how can you maintain a nice flow of fresh air from outside without having the aircon ON as I understand the RECIRC flaps which allow outside air to enter the vehicle close when you switch the Aircon off.

I use mine conventionally as you ask,ECON is on,but in that mode,you can still have it on AUTO,so the vent position is managed,as is fan speed,but you also can manually select vent position too.
I choose to have AIR CON turned on on cold damp days,either on AUTO,or manual vent position.As `Our Graham` would say` The choice,is yours`! ....That was sad wasn`t it!