when I try to use my vents or my defroster I get a white mist/smoke blowing out of my vents. This also immediately fogs my windshield with i'm guessing not normal condensation since it never goes away till I clean it. This is very annoying since it is starting to get cold/and a defroster/heater would be nice. I have no idea whether the heater gets warm because I turn it off since I have to drive. It is a 97 f150 4x4. Does anyone have any ideas?

 

Sounds like you have a hole in the heater core and it will need to be replaced.

 

Yep, major and expensive job. Figure on $600-900 at a shop due to all the labor.

Steve

 

Just had same experiance , Started out with oder then mist , Part was cheap under $100.00 , The entire dash carrier has to come out No short cutsbt removing just glove box either, carrier wont drop down on just one side Good Luck

 

deffinitly a heater core never done it on a f150 but every car I have doen it on has been a pain in the neck it is deffinitly doable though. not the type of job I would pay a garage for its more of a tedious pain in the neck than something that takes special tools or whatever.

 

Could it not be a dirty/clogged/faulty or clogged drain tube on the evaporator? The evaporator will take all of the moisture out of the air and will flow through a drip tube. This is why you always see a water puddle under your car when you stop in the summer. I am not sure but just taking a wack at it if it isnt the heater core.

 

in a high humitidy climate and also low on freon, a frost will build on the evaporator. Then the low presure switch turns compressor off.
The result is a fog off frozen vapor.

oh! if you don't know the compressor is on during defrost to remove humidity from the air. That way from the factory

 

It's the heater core. He's spraying out antifreeze vapor....

When the antifreeze condenses on the glass, it leaves a pronounced film that has to be vigorously cleaned to remove.

Steve