Sweet Smell from AC in 2020 Ford F-150
A sweet smell coming from the AC vents typically indicates a coolant leak, often from the heater core. The sweet odor is due to ethylene glycol in antifreeze. This can lead to foggy windows, reduced coolant levels, and potential engine overheating if not addressed.
Diagnosis Details
Possible Causes
Heater core leak – Coolant leaks into the cabin through the HVAC system, producing a sweet smell when the AC or heat is on.
Coolant hose leak – A leak in a heater hose under the dashboard can allow coolant to enter the vent system.
Evaporator core issue – Less common, but a refrigerant leak (though refrigerant typically smells different) or mold growth can produce unusual odors.
Related OBD-II Codes
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What You Should Do
Check coolant level and look for puddles under the dashboard or on the passenger floor.
Inspect for wet carpets or foggy windows.
If a heater core leak is suspected, have a professional mechanic perform a pressure test and replace the heater core if necessary.
Do not ignore as coolant loss can cause engine damage.
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Disclaimer: This AI-generated diagnosis is for informational reference only. Always consult a qualified mechanic for an in-person inspection. AutOwner is not responsible for decisions made based on this information.
