Why does the Vios air conditioner produce a foul odor?

[JadeLynn]

Vios air conditioner produces a foul odor due to internal dust accumulation, microbial reproduction, and mold growth. Here are the detailed explanations: 1. Dust accumulation: After prolonged operation, dust accumulates on the air conditioner's filter and internal copper sheets. The heat exchanger fins also become filled with dust, and once a certain amount accumulates, it can cause blockages, generating unpleasant odors. When the air conditioner is turned on, these odors disperse into the air. Solution: Disassemble the air conditioner and clean the internal dust. 2. Microbial reproduction: If the air conditioner is not used for a long time, an odor may also occur when it is started. This is because the condensed water retained on the heat exchange coils, fins, and surrounding components slowly evaporates, creating high-temperature conditions around the coils that are suitable for microbial reproduction. The large amount of gas produced during microbial reproduction is released by the air conditioning system, filling the air with odors. Solution: Disassemble the air conditioner, clean the relevant components, and remove the microorganisms. 3. Mold growth: Modern air conditioners have both cooling and heating functions. In many cases, after heating, the indoor unit's interior becomes damp. If the air conditioner is turned off immediately without a drying and anti-mold function, the internal moisture remains, leading to mold growth over time and the natural production of a musty odor. Solution: Clean the interior of the air conditioner and remove the mold.

[DelQuinn]

I've been driving a Vios for several years, and recently the AC has been emitting a musty smell, which is really unpleasant. After researching and consulting with my mechanic friends, I learned that the odor is mainly caused by mold growing on the evaporator. When the AC is on, the evaporator cools the air, producing condensation. If the water isn't drained properly or the drain hole is clogged, moisture accumulates there. In the humid summer weather, combined with a dirty AC filter that hasn't been replaced in time, dust, dirt, and moisture mix together, allowing bacteria and mold to thrive. When the air blows, the smell comes out. Once during maintenance, I saw that the evaporator box was covered in green mold—no wonder it smelled so bad. It's recommended to regularly check and replace the filter, and to run the heater or external circulation for a few minutes before parking to dry out the interior, which works well for prevention.

[Ruth]

My Vios is a commuter car, and I've also encountered the issue of air conditioning odor. This smell is mostly caused by the aging of the cabin air filter. The filter is located in front of the fan, trapping airborne impurities. Over time, it accumulates dust, pollen, and even small insect remains, which, when dampened by moisture, start to emit an unpleasant odor. Especially during the rainy season when the air conditioning is frequently used, poor drainage from the evaporator can make the filter even dirtier, resulting in foul-smelling air. Once, I neglected maintenance for half a year, and by the time I replaced the filter, it was completely blackened—the odor disappeared immediately. Therefore, it's important to regularly check and clean the filter, typically replacing it every few thousand kilometers, and ensure the ventilation system stays dry.

[KiaraLee]

I had a bad smell in my air conditioner shortly after driving my Vios. It turned out to be a usage habit issue. Always using the recirculation mode led to stale air, trapping moisture in the ducts and breeding bacteria that caused the odor. Especially when I turned off the air conditioner immediately after parking, the system didn't dry out, allowing mold to grow in the evaporator and ducts. Later, a mechanic taught me to switch to fresh air mode for a few minutes before turning it off, which significantly reduced the odor.