That sweet, syrupy, almost maple-syrup smell is ethylene glycol - the active ingredient in antifreeze. If you can smell coolant, it is leaking somewhere. Check the coolant reservoir level today.
A small coolant leak is cheap to fix. Ignoring it leads to overheating, a warped head, or a blown head gasket - any of which can total a car. Watch your temperature gauge and top off the reservoir until you can get it diagnosed.
Rubber hoses harden and split with age. The radiator can develop pinhole leaks. The water pump leaks from its weep hole when the seal fails. Look for green, orange, or pink fluid spots under the car.
Get a free vehicle-specific diagnosis →The heater core is a small radiator inside your dashboard. When it leaks, you smell sweet coolant inside the cabin and may see fog on the windshield from the defroster. The carpet under the passenger seat may be wet.
Get a free vehicle-specific diagnosis →A failed reservoir cap will not hold pressure, letting coolant boil over and steam out. Plastic reservoirs also crack with age, leaking coolant onto a hot engine where it vaporizes.
View Full Diagnosis - P0217 →The most expensive cause. A blown head gasket lets coolant into the cylinders, where it burns as white sweet-smelling smoke from the tailpipe. Often paired with overheating and white milky residue on the oil cap.
Get a free vehicle-specific diagnosis →Sweet smell can mean a $20 hose or a $2,000 head gasket. Tell us what you are seeing and we will tell you the most likely cause first.
Get a free vehicle-specific diagnosis →Takes under a minute. Tell us your year/make/model and what you're seeing.
These codes are commonly thrown alongside coolant problems. Click any code for the full diagnosis.
Only if your temperature gauge stays at normal and you can see the coolant reservoir is full. Top off the reservoir and watch the gauge like a hawk. If it climbs, pull over - driving overheated can destroy the engine in minutes.
A sweet smell inside the car (especially when the heater is on) almost always means a leaking heater core. You may also notice foggy windows or a wet patch on the passenger-side carpet. Heater core replacement is labor-intensive.
Days, not weeks - and only if you religiously check the reservoir. A small leak can become a big leak overnight. Get it diagnosed before your next long trip.
A hose is $20-$80 in parts, $100-$300 installed. A radiator is $200-$700 installed. A water pump is $400-$900. A heater core is $400-$1,200. A head gasket is $1,500-$3,000+.