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The heater core is a heat exchanger that serves to warm the vehicle passenger compartment. Outside air or existing air from the passenger compartment is directed over the radiator-like surface of the heater core by the blower motor and into the passenger compartment.



How Does It Work?

  • As coolant is directed through multiple tubes in the heater core, the aluminum fins surrounding the tubes dissipate heat from the engine coolant into the ambient air
  • The heater core has an inlet tube and an outlet tube where coolant is returned to the engine
  • A blower motor fan then pushes the warm air into the vehicle cabin on the demand of the temperature controls
  • Cabin temperature, airflow source and vent location are further controlled by the blend doors per direction of either manual or electronic controls

How Is It Made?

  • Long brass tube with several bends wrapped within many aluminum fins stacked slightly apart.

How Does It Fail?

  • Clogged
  • Deterioration from the inside out
  • Worn out coolant
  • Leaking engine coolant

What are Symptoms of Failure

  • Loss of heating efficiency
  • If a leak is occurring, you may notice that the windshield becomes foggy, a damp spot on the floor and/or a sweet-smelling odor which is emanating from the leaked engine coolant

What Are the Consequences of Failure?

  • Vehicle may overheat and stop running
  • Vehicle may stop working

If you have questions or concerns about heater cores or any of your vehicle’s components, come into your local Pep Boys where we can answer any question, help you find any part, or perform any vehicle service you might need.