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 often indicates a failing AC compressor clutch or low refrigerant, with the smell possibly from mold in the evaporator or a slipping belt.
Diagnosis Details
Possible Causes
Low refrigerant charge due to a slow leak
Failing AC compressor clutch (not engaging at low RPM)
Clogged or dirty cabin air filter causing odor and reduced airflow
Mold or mildew in the evaporator core (causing bad smell)
Related OBD-II Codes
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What You Should Do
Check refrigerant pressure with a gauge set; inspect compressor clutch operation at idle vs.
highway RPM.
Replace cabin air filter if dirty.
Clean evaporator with a foaming cleaner if smell persists.
Have a professional perform a leak test and recharge if needed.
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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.
