Part and system guide
Heater Core
The heater core is a small radiator inside the HVAC case that transfers engine heat to cabin air.
What it does
Uses hot coolant to warm the cabin and support windshield defogging.
Failure signs
- Heater blowing cold
- Sweet smell from vents
- Foggy windshield film
- Coolant loss
- Wet passenger carpet
Maintenance notes
- Do not open the cooling system when hot.
- Use the correct coolant and repair leaks promptly.
- Investigate sweet cabin smell or wet carpet before coolant loss becomes severe.