With A/C

- Coolant leaking visibly into the passenger compartment is a sign of a faulty core or heater hose. A sweet, anti-freeze odor in the car's interior, or a constantly fogged windshield may also indicate a faulty core.
- Inspect the carpet and the area near the floor vents for any signs of moisture or coolant. A leaking heater core may be caused by overpressurization of the cooling system.