If you’ve turned on the heater in your vehicle for the first time this season and were greeted by a sweet, almost syrupy odour, there’s a good chance there may be a leak in the heater core, which is typically located inside the dashboard. The source of the odour is engine coolant, which is circulated to the radiator-like heater core to provide heat inside the vehicle. The problem may also manifest itself as an oily mist blown onto the windshield or even dampness in the carpet. No matter how it’s revealed, get it checked immediately!