Wiktionary(0.00 / 0 votes)Rate this definition: 1  smudge(Noun) A blemish; a smear. 2  smudge(Noun) Dense smoke, such as that used for fumigation. 3  smudge(Verb) To obscure by blurring; to smear. 4  smudge(Verb) To soil or smear with dirt. 5  smudge.
This smell might mean that your coolant is leaking from somewhere like a radiator or heater hose. This kind of a problem means it's a good idea to take your car into a professional. If you smell maple syrup outside the car, this might mean that you have a leaking radiator cap or that the radiator itself has a leak.
Coolant is the fluid that absorbs heat from the engine and then dissipates it through the radiator. It is also dissipated through the heat exchanger in the passenger compartment when you crank your heat in the winter.