Heat Exchanger.
HVAC Heater Core.

Fits C70 (1998 - 2004)

Heater Core
Your vehicle’s heater core handles hot water from your engine’s cooling system and transfers the heat to the cabin in the form of comforting heat from your vents. A failed heater core can leak that water—which is also called coolant or antifreeze—onto the floor on the passenger side. If your Volvo C70 needs to have the heater core replaced, it's a job best left to a Volvo trained technician.