What Causes a Musty Smell in the Car?
2 Answers
Heavy musty odors in the car usually originate from the vehicle's air conditioning system. Here are the relevant explanations: 1. Cabin Air Filter: The cabin air filter primarily functions to filter the air, capturing any foreign particles first. In addition to filtering dust, it can also absorb odors. Failure to replace the cabin air filter for an extended period can lead to clogging, not only reducing airflow but also intensifying odors. 2. Evaporator Core: Outside air passing through the evaporator core inevitably carries moisture and dust. While most of the moisture and dust are expelled from the vehicle via the AC drain, a small portion may adhere to the evaporator core. Over time, this can cause mold growth, producing a sour, rotten smell. This is an easily overlooked area and one of the reasons why the source of the odor can be hard to identify.
I often encounter this issue. The musty smell is mostly caused by moisture not dissipating in the car. For example, after turning on the AC, condensation forms inside, leading to mold growth. This is especially noticeable when the cabin air filter hasn't been replaced for a long time, accumulating dust and mold. Another common cause is water leakage, such as from aging sunroof seals or clogged door drain holes, which can soak the carpet and develop mold within days. Food crumbs falling under the carpet and rotting can also cause bad odors. If you notice a musty smell, address it immediately, as bacteria can affect respiratory health. Simple solutions include leaving windows open for half a day after parking or having a professional clean the AC and carpets—it's not expensive but crucial for health. Regularly, avoid closing windows completely when parked and place a bamboo charcoal bag to absorb moisture and prevent mold.
