Condensation may develop in the heater case which can cause a musty odor from the heating, ventilation and AC (HVAC) system. Our technicians tell us a cleaner is available for the heater case. Also, the drain system should be checked for debris.Google+
Car Problem Reports
Volkswagen Passat Odor from HVAC vents
Volkswagen Passat Problem
Average Mileage: 41,000 mi (40,000 mi - 42,000 mi)
Visitor, 2009 Volkswagen Passat, 42,000 mi
musty smell in cabin. Not fixed as yet
Musty smell from a/c unit upon every use.