Misting up windows on frosty mornings ... Help

[sukrw]

Hope someone can help me ... well my A3 ...

Over the past couple of mornings it has been very cold - frozen windows. I open the car, get in, start the engine and then press the Clear Windscreen button on the heater control panel - this (I assume) redirects very fast blown air directly to the windscreen). I then get out, scrape all the frost off the windows. But when I get back into the car (2 mins later) all the windscreen and front side windows are all misted up quite badly and it takes about 5-8 mins before they clear.

Any ideas why this is doing this ? It has never done it on a non-frozen day. This morning I checked when i got into the car and the windows on the inside were NOT misted up. But after going through the procedure (above) they were all misted up.

Does the Clear Windscreen button turn OFF the A/C ?

I can't see any signs of water in the car at all - foot wells and boot etc. And this only occurs when it is frozen outside. I did wash the car the previous weekend but no misting up until it freezes outside.

Next time, I will try not using the Clear Windscreen button but set the A/C to blow at max speed onto the windscreen and see if it still does it.

Anyone else get this ?

The car is an A3 sportback 2.0 tdi Feb 2007.

Many thanks.

Sukrw.

[Col]

Normally caused by a damp pollen filter. The air is obviously drawn through the filter and as it does it picks up some moisture.

Dirty / old pollen filters are more prone to this than new / clean ones.

[sukrw]

ah right, many thanks for the advice.

Sorry to sound a bit thick, but would you know where the pollen filter is located and how to get it out to check ? Once out, can it be placed on a warm radiator in the house for a few hours to dry out ?

I did wash the car the weekend before all this started (but it has only been frosty this week so not seen it before). Can the pollen filter become wet/damn from car washing (inc. hosing down) ...?

Only had the car for a month or so .... so not clued up on it all yet.

Many thanks

Sukrw.

[engineermk]

you could try manually selecting; recirc, high fan speed and direct on to the windscreen. this will stop outside air being drawn in through the pollen filter.

[sukrw]

Will try that too ...

I have found the pollen filter off this thread (if anyone else needs to locate it)

http://forums.fourtitude.com/zerothread?id=2838865

I have removed it (it didn't feel damp but then it is -2 out there so couldn't feel much with cold fingers !) I have brought it inside and near a warm rad to try and dry it through.

Will let you know if it works (prob next time it is v. cold outside !)

Thanks .

[ini]

Could also be a slight leak in the heater matrix.

A little radweld will cure it.

[sukrw]

how would I know if there is a leak in the matrix ?
the water level dropping down over time ?

I hope not as the car is less than 1 year old - so it would be straight back for warranty :)

Thanks.

[ini]

Instead of clearing the windscreen, the fan causes it to fog up.

If it is new it is unlikely to be a damaged matrix.

The windscreen will also stay misty longer if it is dirty/greasy inside.

[MSB]

I have this problem too, but have just put it down to the cold and damp mornings. However, I have also noticed that if you use de-icer on the windcsreen the misting is worse ! Try leaving the windows or doors open when using the de-icer, it helps a bit (i think!)