
Musty Odor After Rain in 2019 Nissan Altima
A musty smell after rain typically indicates moisture intrusion, often from a clogged A/C drain, leaking sunroof drains, or a wet cabin air filter. This can lead to mold and mildew growth, affecting air quality and potentially causing respiratory issues.
Diagnosis Details
Possible Causes
Clogged A/C evaporator drain tube causing water to accumulate and produce a musty odor.
Blocked or disconnected sunroof drain tubes allowing water to leak into the cabin.
Wet or contaminated cabin air filter from moisture ingress.
Leaking windshield or door seals allowing rainwater to enter the vehicle interior.
Not satisfied with this diagnosis?
Try Another DiagnosisWhat To Do Next
What You Should Do
Inspect and clean the A/C evaporator drain tube; check sunroof drains for blockages; replace the cabin air filter if wet or moldy; examine door and windshield seals for leaks.
Use a moisture meter to locate damp areas and dry thoroughly.
Consider using an antimicrobial treatment for the HVAC system.
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.

