Where Does the Strong Musty Smell in the Car Come From?
4 Answers
In-car musty odors primarily originate from the vehicle's air conditioning system. Below is a detailed explanation of the sources of musty smells in cars: 1. Cabin Air Filter: The cabin air filter is responsible for filtering the air, trapping any foreign particles before they enter the system. Besides filtering dust, it also absorbs odors. Failure to replace the cabin air filter for an extended period can lead to clogging, which not only reduces airflow but also intensifies unpleasant odors. 2. Evaporator: The evaporator is essential for achieving cooling effects. As outside air passes through the evaporator, it inevitably carries moisture and dust. While most of this moisture and dust is expelled from the vehicle through the air conditioning drain, a small portion remains attached to the evaporator. Over time, this can lead to mold growth, producing a sour, rotten smell. This is often an overlooked area and one of the reasons why the source of the odor can be hard to identify. In such cases, it is necessary to have a professional technician clean the vehicle's air conditioning system.
That unpleasant musty smell in the car, which I often encounter while driving, is usually caused by excessive humidity inside the vehicle. For example, the air conditioning system is a major issue—if the filter isn’t replaced in time, accumulated moisture can breed mold, especially after summer use without proper drying. The carpets and seats in the car are also culprits; if they get wet from rain or spills and aren’t dried thoroughly, trapped moisture can lead to mildew. I once parked in a humid, tree-heavy area, and with the windows closed for too long, poor air circulation caused the musty smell to develop. External factors also play a role—aged door or sunroof seals can allow rainwater to seep in, gradually causing odors. Regularly ventilating the car is crucial, especially leaving windows slightly open for a few hours after parking or placing bamboo charcoal bags to absorb moisture, which effectively prevents the issue. When cleaning, don’t just focus on the surface—treating the AC ducts with mold remover can better prevent recurrence.
As someone who frequently takes children out, I'm particularly concerned about the musty smell in the car because it's not only unpleasant but also harmful to health. The source is mostly mold in the air conditioner's evaporator or filter, and long-term neglect can lead to bacterial growth. High humidity in the car is also a major cause, such as not opening the windows promptly after parking in the rainy season, or carpets and seat covers absorbing moisture and not drying thoroughly, allowing mold to spread. Children's snacks or spilled drinks left uncleaned can ferment and grow mold over time. External factors like leaks in the body gaps or clogged wiper troughs can allow water to seep into the floor, causing odors. I've found that using dehumidifiers and regularly changing the air filter can help alleviate the issue significantly; otherwise, it can easily trigger allergies or respiratory problems.
There is a musty smell in the car, and I think the main sources are moisture and poor ventilation. Mold in the air conditioning system is the most common issue; when the filter is clogged, damp air cannot circulate, leading to mold growth. Interior components like carpets or leather seats absorb moisture and are prone to deterioration, especially when parked in shady areas. Rainwater seeping in through doors or the trunk can also accumulate, fermenting and producing unpleasant odors. It's recommended to park in dry places whenever possible, regularly use the external air circulation for ventilation, and clean the interior with natural mold removal methods like white vinegar spray, which is safe and eco-friendly.
