I am having a real issue here. The winter time here is nice but often brutal. I usually come home from work after dark so you can imagine the temperature drops from 60 degrees to about mid 30s to low 40s.

This whole time I have not been able to use my heater at all. What happens when I turn on my heater, is the windows fog up to the point where I cannot see anything in front of me. I turn on my defroster and it only makes things a lot worse.


After I get done driving the car like this, it looks like ice is forming from inside the car.

Do you guys have any ideas as to what this could be?

 

more than likely the heatercore went south.

 

That's the first thing I thought of also. It's not that your windows are fogging up. You're putting an antifreeze coolant mist on the windows.

 

heater core is less than 5 years old though, how long do they typically last?

 

6 months to 20 years

 

Yea, that's what came to mind to me too. Right before my heater core went, I got really bad interior fogging. Perhaps you have a slight leak on it?

 

throw some "Fog X" on it. it might help.
POZ

 

You also should smell antifreeze if its the heater core.

 

I hope you are running that non-toxic anti freeze.

Cause if not your slowly poisoning yourself and others in the car breathin that stuff.


If n doubt dump some stuff in it.
aluminumseal or even do a myth buster egg trick.

Wont be a perm fix but should narrow it down easy if it stops for a bit.

But yea, that is a sure sign you got a bad heater core.

Unless...... if you got parts from one of them flush n fill kits, use the plastic connector to unhook and bypass the heater core. If it still fogs up, not the heater core.

I do that in the summer time in both of my non AC cars. Shouldn't "matter" but they both are cooler inside the car when I bypass them.

I had similar problem but obviously wasn't the heater core when it still did it when it was bypassed. Turned out to be just moist inside. A box fan on high with the windows cracked runnin for 3 days solved it for me.

 

well I used my heater all last year and it worked incredibly well. Kept me nice and toasty, absolutely no issues with the defrosters, and no issues with the windows fogging up either.

All of a sudden this year, that became a big issue for me.

EDIT: I wanted to add in that I sincerely doubt it is the heater core. I say this not because it is less than 5 years old, but the fact that I am losing no coolant, my interior doesn't reek of coolant when I use the heater, and there's no moist on the passenger side carpet of where the heater core is. And my car doesn't overheat.

I mean could it be anything else but the heater core?

 

I had A Mustang and the same thing was going on.And the carpet was not wet and couldn't smell antifreeze but the heater core was bad.It never got hot I think it was such a small amount leaking at a time I never noticed.

 

has it been around freezing temperatures? it might have frozen and then cracked.
you will not lose much if any coolant if it has a small crack, because its just a little steam spraying, not a lot of coolant

to test if its your core, take the inlet and outlet to the core, and link them,, this will bypass the heater core, and SHOULD give you a non steamy windshield. does it fog up when the vent is closed and fan is off?

 

You can get your cooling system pressure tested. If pressure leaks down or coolant starts to puddle on the passenger side floor then there's a bad leak somewhere. As mentioned above, you don't need a big leak to put a coolant mist on the windshield.

Does you car have AC? When the defrost is on, the AC is also working. It dehumidifies the air for the defroster.