AC Not Cold and Bad Smell in Traffic
The AC works well at highway speeds but loses cooling in stop-and-go traffic, accompanied by a bad smell. This suggests a failing AC compressor clutch, low refrigerant, or a clogged evaporator/condenser. The smell may indicate mold or bacterial growth in the evaporator case.
Diagnosis Details
Possible Causes
Failing AC compressor clutch or low refrigerant charge – common in Silverado models, causing intermittent cooling.
Clogged or dirty evaporator core or cabin air filter – restricts airflow and causes musty smell.
Faulty AC pressure switch or expansion valve – affects cooling at low engine RPM.
Related OBD-II Codes
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What You Should Do
Check refrigerant level with a gauge; if low, inspect for leaks.
Test compressor clutch engagement at idle.
Replace cabin air filter if dirty.
Use an AC evaporator cleaner to eliminate odor.
If clutch fails, replace compressor assembly.
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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.
