A sweet antifreeze smell inside your 2023 Chevrolet Equinox's cabin typically points to a heater core leak. The heater core, a small radiator inside the dashboard that provides cabin heat, can develop leaks that release coolant vapor directly into the interior.
How Heater Core Leaks Cause Interior Smell
The heater core is located inside the HVAC housing behind the dashboard. Hot coolant from the engine flows through it, and a fan blows air across its fins to heat the cabin. When the core develops a leak, coolant escapes into the HVAC housing and evaporates, sending sweet-smelling vapor through the vents.
Symptoms of Heater Core Leak
Beyond the antifreeze smell, heater core leaks cause foggy windshield that won't clear with defrost, damp or wet carpet on the passenger side floor, coolant level dropping without visible external leak, oily film on windshield interior, and reduced heat output from the heater. Severe leaks may drip coolant onto the passenger floor.
Distinguishing from External Leaks
External coolant leaks produce smell from the engine bay that enters through ventilation. Heater core leaks smell specifically from the vents when the fan runs, may fog only the inside of the windshield, and often cause passenger side floor wetness. The smell may be present with the heater off if the core is severely leaking.
Repair Considerations
Heater core replacement is labor-intensive as the dashboard must typically be partially or fully removed for access. This makes the repair expensive despite the heater core itself being moderately priced. Some owners delay repair due to cost, but coolant vapor is harmful to breathe and continued leaking can damage interior components.
Temporary Measures
If immediate repair isn't possible, you can bypass the heater core by connecting the heater hoses together, eliminating the leak but also eliminating cabin heat. This is a temporary solution only practical in warm weather. Monitor coolant level and have proper repairs made as soon as feasible.