Bad smell and steam from engine

Hey guys, I have a 2000 Subaru Legacy AWD wagon with 72000 miles on it. It has a 4 cyl. 2.5 engine. The problem I'm having is a bad smell that fills the interior after driving for a while. While driving around, I don't smell anything, but as soon as I come to a stop or shut off the car, the cabin fills with the smell of hot or burning rubber. I also notice some steam coming from the front grill. I opened the hood and can smell burning rubber, but can't isolate where the smell or steam is coming from. The radiator is full of fluid, the temperature gauge does not move past the first mark and there are no fluid leaks or spots on the ground underneath. I have noticed that my cooling fan does not seem to be running when the car is idling. Also, when I'm driving and running the heater, I can't detect that smell inside the car. Only when I stop. What could be going on?