Ice on inside of windscreen?!

Speedbird

Active Member
Aug 10, 2018
268
135
With the cold weather this week, I'm experiencing a problem on my Leon ST which I have never had before.
It is a 65 plate, 37k mile tdi 184.

In the mornings my Leon has had ice on the inside of the windscreen. Yesterday, I mopped up the residual water on the screen after it had melted, drove to work with the heater on full, then opened the windows for a few minutes to get the warm moist air out. I then cleaned the inside of the window with AG car glass polish, and put a desiccant bag on the dashboard. Got up this morning, and exactly the same problem!

Never had dogs in the car, usually just myself using it, no sunroof and cant see any signs of leaks.

Anyone else experiencing this? Previous car was a Ford Kuga with a heated windscreen. Never iced up inside, and any condensation was gone within 30 seconds because of the heated screen.
 

Deleted member 103408

Guest
Had ice on the inside this morning on both my 2014 Cupra and 1 year old Transit Van.
 

surrealjam

Active Member
Jan 8, 2015
328
53
I've not had this on my 14 plate Leon, 16 plate Golf or 18 plate Leon. But I know it's quite a common complaint still. You must have water getting in from somewhere but it could be a right game finding out where
 

SRGTD

Active Member
May 26, 2014
2,414
1,298
Formation of condensation could just be the effect of the extremes of temperature inside / outside the car when it’s exceptionally cold outside, rather than water getting into the car.

A similar effect used to be found on the inside of house windows - those of you who can remember living in houses before central heating and thermally efficient windows (I can!) may have experienced this. It wasn’t uncommon for condensation to form on the inside of single glazed house windows in winter because of the contrast between the warm air inside and the cold glass surface. In freezing wintry conditions, this condensation would then freeze on the inside glass surface overnight when whatever was being used as the heat source in the room(s) was no longer working and the room temperature dropped. Sometimes, the ice patterns were pretty impressive!
 

gletts

GL53TTS
Jan 7, 2008
121
8
Crawley, West Sussex
I also have this on my 2016 FR ST 184, and also had it on my Mk2 FR (petrol).

Interestingly, I've never had it to the same extent on any other car I've owned in recent years (Mk1 Leon FR+, Vectra, Mazda 6, Exeo, Citroen C2).

I have noticed it's far worse, if you get a day where the temperature outside is cold, but the sun is out. Then as the sun goes down, the condensation forms on the inside of the windscreen, and if it's then freezing outside, it freezes. Even if the car is driven in the evening (and therefore condensation cleared), it is still very bad the following morning after those weather conditions. My driveway doesn't get any sun first thing in the morning, which doesn't help.

I can only put it down to either the rake of the windscreen on the Leon - both the Mk2 and Mk3 have quite raked windscreens in comparison to the other cars I listed above, or moisture being held in the air conditioning system. I've not noticed any 'damp' areas in the car - other than when the boot is opened and it's wet, water drips (pours!) into the boot due to the design.

A lot of my journeys are short, so the car doesn't always warm up, but that was the same for all the above cars. The Leon 184, and the Exeo both take a very long time to warm up (10 mins plus to get any warm air). The others were blowing warm air within 5 minutes.
 

Speedbird

Active Member
Aug 10, 2018
268
135
Hmm, maybe it is a common occurrence then and not just my car.

Gletts, interestingly I have noticed this about my FR ST 184 aswell, it takes a lot longer to warm up than any of my previous cars. Sometimes I have to do very short journeys (>2 miles) and the car doesn't even go up one bar on the temperature guage. In comparison, my Kuga was at full engine temperature by the end of the same journey.

I also do a lot of longer journeys, especially in the summer (mountain biker), hence buying a diesel.
 

gletts

GL53TTS
Jan 7, 2008
121
8
Crawley, West Sussex
Bendy, yes a lot of my journeys are around 1.5-2 miles (home to office) and same as you - not even one bar on the temp gauge. Thank goodness for heated seats! My parents used to have a Leon FR 150 (diesel) which was the same.

I do some longer journeys too - I leased the FR 184 diesel because (at the time, 3 years ago) it was significantly cheaper than the FR 1.8 TSI.

However times have changed, and am about to take delivery of a new FR Sport 190 TSI DSG, which is almost £50 per month less to contract hire than the FR 184 is!
 

Mr Pig

Active Member
Jun 17, 2015
2,617
906
Recently I've had water inside the windscreen on both the Leon and Ibiza. I doubt it's anything wrong with the car. It's probably just due to atmospheric conditions at the minute and maybe the way the heater is used?
 

Walone

Active Member
Feb 10, 2016
1,548
426
Near Heathrow
I've never had this on any car that didn't have A/C, I think when the evaporator defrosts the resulting water causes heavy condensation on the inside of the screen which then freezes when there is a heavy frost.
 

Mr Pig

Active Member
Jun 17, 2015
2,617
906
I've never had this on any car that didn't have A/C

I never use the AC to clear the window for that reason. My Madza 6 was terrible. If you cleared the window with the AC, as soon as you switched the AC off the glass misted up again! Clear it without the AC it takes slightly longer but stays clear.
 

rcopus

Active Member
Jun 6, 2012
270
8
Midlands
I find the opposite but all car's I've owned have had climate control.
I never turn the AC off and let it do its thing, never had water inside the car and certainly not ice.

On all of these cars the window de-mist function runs the AC with heat, the reason being that it is going to reduce humidity in the air, like all AC systems do.

The evaporators in the car should be draining to outside of the car not just dumping it inside. Otherwise when you used the AC in summer you'd end up with a soggy mouldy car.

Trying to de-mist the glass by simply increasing the temperature of the car is just causing the moisture to evaporate and then condense again once you leave the car overnight. So by never using the AC you'll just be in a never ending cycle.
 

SRGTD

Active Member
May 26, 2014
2,414
1,298
I find the opposite but all car's I've owned have had climate control.
I never turn the AC off and let it do its thing, never had water inside the car and certainly not ice.

This is what I do. My AC has been on since I got my car nearly three years ago and I’ve never had any issues with water or ice inside the car.
 

gletts

GL53TTS
Jan 7, 2008
121
8
Crawley, West Sussex
Me too - I never turn the AC off, and just let it do its thing. I think I'm right in saying that when the temperature outside is below about 3-4 degrees, the AC unit does not come on though?

Mr Pig - I remember that from my Mazda 6 (mark 1 facelift 2007) - if you turned the AC off, and it was a damp day, the windows almost instantly misted up. Again I just used to leave it on all of the time - mine had climate control, not manual AC.
 

Mr Pig

Active Member
Jun 17, 2015
2,617
906
Again I just used to leave it on all of the time - mine had climate control, not manual AC.

Yeah, mine did too but I still prefered just not using the AC. Don't see the point of AC unless it's hot outside.