Window fog

[Dirty35]

Having a weird issue where my window is foggy but the defrost doesn't take care of it .. And sometimes ends up filmy .

Now I know it could be a heater core . Except it doesn't fog up with heat.. No coolant smell.. No leaks in the floorboard etc basically no symptoms

I also have my whole front windshield tinted . Wondering if the moisture is somehow reacting with the tint ?

I can clean the window and it's fine for days even with heat on or ac . But another cold morning and it kinda sticks .

Anybody have any advice ?

[Dirty35]

And to add some info it only seems to affect a 10 inch area (across) in the middle of my front window .

[Ilya]

My front is tinted too, so it's not that.

When you turn your AC/Heat on, do you feel it coming from the vents in the dash by the window?

[Dirty35]

There is air coming out of the dash because it'll clear most of the window minus the middle .. Just seems to hang in there.

[Dirty35]

Leaving work I'm checking and it seems the problem area doesn't have air actually hitting it .. Like 3 inches on either side of the divide for the vents isn't blowing .

[Double E]

it's antifreeze. That's the only way it would be filmy. That it does not smell probably means it's a little less concentrated and possibly old. You might do a pressure test on the coolant system to confirm.

One other way to test is to bump up the temp of the air when this occurs. if it still fogs up, and is also filmy, it's not water vapor.

[Larz]

Sometimes, while driving at night after a storm, when the air has that humid, sticky feel, There is a bit of fog on the outside lower middle of the windscreen when the air/con is running. I find that if I switch the 'auto upper vent' to OFF, it goes away. Not sure if this is what you're describing.

[Dirty35]

it's antifreeze. That's the only way it would be filmy. That it does not smell probably means it's a little less concentrated and possibly old. You might do a pressure test on the coolant system to confirm.

One other way to test is to bump up the temp of the air when this occurs. if it still fogs up, and is also filmy, it's not water vapor.

My coolant was just flushed and serviced by the dealership about a month ago.. Getting into cold months I doubt they would've diluted it anymore then necessary.. I cleaned it off last Friday and have had hot and cold weather but hasn't returned .. I'm playing with it was a dirty window and it just clung dirt when it would fog a bit. Haven't been loosing coolant in the overflow either , I've been checking so I'm just gonna keep my eye on it . Thanks for the reply