Sweet Smell from AC in 2020 Chevrolet Silverado 1500
A sweet smell coming from the AC system in a 2020 Chevrolet Silverado 1500 typically indicates a coolant leak. The heater core, which uses engine coolant to warm the cabin, may be leaking coolant into the HVAC system. When the AC is on, the evaporator can condense moisture and mix with the coolant, producing a sweet odor. This issue requires prompt attention to prevent further damage or health risks.
Diagnosis Details
Possible Causes
Leaking heater core: The heater core is a small radiator inside the dashboard that circulates hot coolant. A crack or pinhole leak allows coolant to escape into the cabin air, creating a sweet smell.
Coolant leak from hoses or connections: A leak in the heater hoses or their connections near the firewall can allow coolant to drip into the HVAC intake area.
Evaporator drain blockage: If the AC evaporator drain is clogged, condensation can mix with leaked coolant, intensifying the smell.
Related OBD-II Codes
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What You Should Do
Inspect the cabin for coolant puddles or wet spots under the dashboard.
Check the coolant level in the reservoir and look for signs of leakage around the heater hoses and firewall.
If the heater core is leaking, it will need to be replaced, which is a labor-intensive job often requiring dashboard removal.
Have a professional mechanic diagnose and repair the leak to avoid engine overheating or interior 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.
