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.
The cause of the smell is fungus, mold, and/or bacteria living in your vehicle's climate control system (typically they congregate in the evaporator core and/or near the condenser in your A/C unit).