Ouch is right! The problem with car is a leaking heater core. It looks like a radiator yet smaller - it resides right behind the center of the dashboard in that car and when you want heat and turn on your fan or defroster - the blower motor and fan take the heat from this core and direct it into the car. The foul smell is anti-freeze and it can make you sick after a while. It needs to be fixed before it blows and you smoke your engine due to overheating. Good Luck.
"Life's too short to drive slow!"
My first name is Anne - was a Ford Dealer Service Manager for 11 years. Waiting for my new Expedition to come in (woo hoo!)