AC Not Cold and Smells Bad in Traffic
The AC works well on the highway but loses cooling in stop-and-go traffic, accompanied by a bad smell. This typically indicates a failing or clogged cabin air filter, a dirty evaporator coil, or a refrigerant leak that becomes more apparent at low airflow.
Diagnosis Details
Possible Causes
Clogged or dirty cabin air filter restricting airflow, causing poor cooling and musty odors when the car is stationary.
Evaporator coil covered in mold or debris, leading to reduced heat exchange and a foul smell when the AC is running.
Low refrigerant charge due to a small leak, which is more noticeable at idle because the compressor works less efficiently at low RPM.
Faulty AC compressor clutch or condenser fan not engaging properly when the vehicle is not moving, reducing cooling capacity.
Related OBD-II Codes
Not satisfied with this diagnosis?
Try Another DiagnosisWhat To Do Next
What You Should Do
Start by replacing the cabin air filter and inspecting the evaporator drain for blockages.
If the smell persists, have the AC system checked for refrigerant pressure and leaks.
Clean the evaporator coil if mold is present.
Ensure the condenser fan operates when the AC is on.
Related Repairs
Share this diagnosis
Help others with similar symptoms
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.
