AC Not Cold with Musty Smell
The musty smell when the AC is on, combined with reduced cooling, typically indicates mold or mildew growth in the evaporator case or a clogged cabin air filter. This can also be caused by a refrigerant leak or a failing compressor, but the odor points to moisture and microbial buildup.
Diagnosis Details
Possible Causes
Clogged or dirty cabin air filter causing musty odor and reduced airflow.
Mold or mildew on the evaporator coil due to moisture accumulation.
Low refrigerant level (leak) reducing cooling capacity.
Faulty AC compressor or expansion valve.
Related OBD-II Codes
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What You Should Do
Replace the cabin air filter first.
If smell persists, have the evaporator case cleaned professionally.
Check refrigerant pressure and inspect for leaks.
If cooling is still poor, diagnose compressor and expansion valve.
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.
