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.
More often than not, when you have an external leak, the coolant escapes and your car quickly overheats. Most likely you can easily spot where the leak is coming from by looking at it; a split or broken hose or a hole in the radiator are two good examples. Leaks in the water pump, heater core, or engine freeze plugs can also allow coolant to escape.