Window de-fogging

If this is coming from the inside, then your heater core is leaking and needs to be replaced.

If it's coming from the outside, then you have a leak somewhere in the engine compartment that needs to be fixed.

You can find the leak by pressurizing the system and looking for it.

You need to correct this issue before your engine overheats and blows a gasket.

This is inside I presume? And have you addressed the coolant leak at the heater that is deposition the antifreeze in vapor form, if not you will not stop it.

Mark (mhpautos)