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Q: Problem is when I turn on my heat the inside of my car fogs up.

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The heat in my car blows warm but every time I turn it on, fog blows out of the vents and the whole inside of my car fogs up and I cannot see out of my windows. I can see the fog blowing out of the vents and can smell it. Could it be the heater coil even though there is no moisture on the floorboards of my car?

My car has 225000 miles.
My car has an automatic transmission.

Hi There, It sounds like you may have a leak in your heater core causing the moisture to be heated up resulting in the fogging up of your windows. The [heater core]((https://www.yourmechanic.com/services/heater-is-not-working-inspection) is a small radiator like unit that circulates the hot coolant from the engine through the heater core which then uses this warm coolant to heat the inside of the car with the help of the blower motor that blows the warm air through the vents inside the car. When this leaks, this can result in the heater not working properly or producing a fog or moisture inside the cab of the vehicle as you describe. I would suggest having an expert from YourMechanic come to your location to diagnose your heating system.

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