Why does my Toyota windscreen/windshield fog up even in dry weather?

Question

This is a new Toyota Aygo and the windscreen gets fogged up even when it's not raining, I've tried re-circulate and various other settings in the car and it doesn't seem to help. The only thing that works is blasting the air conditioning through the defrost outlets onto the window.

Answer 1

I agree with the other suggestions about a possible coolant leak from the heater core and/or a clogged air conditioner drain, however this is a new Toyota! I think it could be outgassing from the plastic dashboard, carpets, seats, etc. becoming redeposited on the inside of the glass.

Suggestions: wipe the inside of the glass with Windex or another ammonia-type cleaner. If possible, park with your windows open to ventilate the inside of the car. Your problem should decline as the plastic materials outgas less over the next few months. Unless it's pouring or freezing outside, use outside air (not recirculate) through the ventilation system, to blow away the outgassing plastic vapours as much as possible.

Answer 2

If it's something like a grey film, rather than condensation (if you follow me, it ain't easy to describe a visual effect) I'd go with Andy.

I've never been sure if it's something given off by the new materials or if it's something from whatever they use to prepare the car, but I've had it happen to me with brand new cars. Just clean the glass and try to ventilate the car as much as possible, it'll go away eventually.

I might add if you've been using the aircon and turn it off, you will sometimes get condensation form.

Always use fresh air rather than recirculate whenever possible. If you're worried, take it back, it's under warranty.

Answer 3

Acouple of things could be happening. First if the vent tube for the ac drain is plugged water will build up in the hvac box and cause moisture to be picked up in the vent system.Second if your heater core is leaking coolant builds up inside the hvac box and same as above happens. Also check the fresh air intake duct to make sure they are not plugged.

P.S
if your getting a sweet smell in the car when you turn on the heater its the heater core that's leaking

Answer 4

you have a bad heater core i think,,i own a repair shop,and that sounds like its blowing a mist of coolant up on the glass causing this to happen,and the cold from the air conditioner will make it clear off,you might want to check the floor of your car ,and see if its damp,,or wet,,that might be a good sign it is leaking some,,these are pretty hard to put in,so make sure that's it before you tear it apart,,but in my 36 years of doing this,,that sounds like what it is,,good luck with it,i hope this help,s.,,have a good x-mas.

Answer 5

if its still under warrenty take it back
could be a no. of things
bad sealarond window, heatermatrix leaking, bad door seals?