- One of the most common reasons for a foul smell coming from your heater/AC is mold and mildew growth.
- Over time, moisture can accumulate in the AC evaporator core and drip tray.
- Warm and moist conditions provide an ideal environment for mold and mildew to grow and multiply, releasing a musty or sour odor into the cabin.
2). Dirty Cabin Air Filter:
- A dirty cabin air filter can trap pollutants, dust, debris, and even harmful bacteria.
- As air passes through the clogged filter, these contaminants can build up, causing a foul smell.
3). Dirty Evaporator Coil:
- The evaporator coil in the AC system is responsible for absorbing heat and moisture from the air.
- Dirt, dust, and other debris can accumulate on the evaporator coil over time, reducing its efficiency and creating favorable conditions for mold and bacteria growth.
4). Dirty Blower Motor:
- The blower motor is responsible for circulating the air inside your vehicle.
- If the blower motor is dirty, it can accumulate dust and debris, which can become airborne when the fan is turned on, resulting in unpleasant odors.
5). Leaking Coolant:
- If your heater core is leaking coolant, the sweet smell of ethylene glycol can be detected in the cabin.
- A coolant leak can also lead to a decrease in your vehicle's coolant levels and potentially cause overheating.
6). Exhaust Fumes:
- In rare cases, a bad smell in the cabin can be due to exhaust fumes entering your vehicle.
- This could indicate an exhaust leak, which should be addressed immediately for safety reasons.
