Sweet Smell from AC - Possible Coolant Leak
A sweet smell coming from the AC vents when the system is on typically indicates a coolant leak, often from the heater core. The sweet odor is characteristic of ethylene glycol-based antifreeze. This can lead to engine overheating and interior damage if not addressed promptly.
Diagnosis Details
Possible Causes
Leaking heater core (coolant leaks into the cabin through the HVAC system)
Leaking coolant hose or connection near the heater core
Cracked or damaged radiator or overflow tank (less common with AC-specific smell)
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 coolant residue around the heater core area.
If confirmed, the heater core likely needs replacement.
Do not drive with low coolant to avoid engine damage.
Related Repairs
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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.
