2002 BMW 330 Awful smell from the vents

NHPD1017

MEMBER
2002 BMW 330
6 CYL
2WD
AUTOMATIC
75,000 MILES

Recently, when I turn on the heat, everything works however, a awful smell comes through the vents and smells up the whole car. It almost smells like mildew or musk. At first I thought it was sour milk because my kid left a milk carton under the seat.I hit the carpet with febreeze. And there is no smell in the car when it sits for awhile. Until I start the car and put the heat on.

2 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Welcome to 2carpros and TY for the donation

AC/Heater unit If a vehicles air conditioner blows out air that smells like the inside of old gym sneaker when the A/C is turned on, microbes are growing on the evaporator. Mold likes damp, dark places. Bacteria can also thrive under such conditions. Besides smelling bad, it can be unhealthy to breathe (ever hear of Legionnaires Disease?).

To get rid of the unwanted organisms, various chemicals can be sprayed on the evaporator directly or through the blower ducts or air intake. Many replacement evaporators have a special chemical coating that inhibits the growth of mold and bacteria. The drainage tubes that carry condensation away from the evaporator should also be inspected and cleaned.