
When the air conditioning is turned on, there is a strong moldy smell coming from the vents. The reasons and solutions are as follows: 1. Long-term lack of cleaning: If the air conditioning filter has not been cleaned or replaced for a long time, dust accumulates too much and ferments with the internal water vapor of the air conditioning system, resulting in a moldy smell. Regularly clean and replace the filter. 2. Dust mixed with condensed water: Dust entering the evaporator and mixing with condensed water can also produce a moldy smell over time, eventually turning into a sour smell. In this case, the evaporator needs to be cleaned. It is best to have it cleaned by 4S staff to avoid damaging the components. 3. Ventilation ducts: Due to the large temperature difference after the air conditioning is turned off, water vapor in the ventilation ducts condenses into water droplets. Over time, mold can grow in the ducts, causing odors. The ducts can be cleaned periodically when replacing the filter.

When I encounter a foul smell in my car, I start by checking the simplest possible causes. Common reasons include food debris rotting under the carpet or in seat crevices, or a broken fruit bag in the trunk leaking juice and causing odor. I park the car in a safe place, turn off the engine, and then use a flashlight to thoroughly inspect all corners, including the floor, under the seats, and the air vents. If I find any rotting material, I vacuum it up completely, spray some baking soda solution to scrub the stained area, let it dry, and then vacuum again. Don’t forget to open the windows for several hours to let fresh air replace the bad odor. If the smell persists, it might be mold growing in the air conditioning system, in which case I turn the fan to high and blow hot air for half an hour to disinfect. For prevention, I’ve developed the habit of cleaning up any trash inside the car every time I get out, avoiding leaving perishable items inside. Regular deep cleaning at a car wash is also a good idea to ensure a healthy interior environment.

I've also experienced foul odors in the car. At first, I thought the air conditioning was broken, but it turned out to be cookie crumbs my child dropped under the seat that had rotted. The solution is actually quite simple: First, after parking, take some time to search, focusing on the trunk, carpet edges, and glove compartment area. Feel around with your hands for anything sticky. Once you find the source, sprinkle baking soda on it and let it sit overnight. The next day, use a toothbrush to clean it and then vacuum thoroughly. Second, open the windows to ventilate for a whole day, while turning on the air conditioning's external circulation to blow out the odor. Third, if the smell persists, the air filter might be dirty—just replace it with a new one. Fourth, in daily life, I teach my child not to eat in the car and to check for any leftover trash before getting in. These simple steps can solve the problem—no need to panic. Keeping the car dry is key.

As someone who drives the family car daily, I've dealt with this issue several times. Kids always spill juice or leave chip crumbs in the car, which can rot and stink if not cleaned promptly. After parking, I first vacuum the carpets and seats, then wipe off stains with a damp cloth. If the odor persists, it might be mold in the AC system requiring a filter change. Placing coffee grounds in corners helps absorb smells, and airing out the car with windows open for a day also works. For prevention, avoid eating perishable foods in the car, and regular cleaning is fundamental.

A rotten smell in the car is usually caused by residue or stagnant water. I will park and check the air conditioning intake and drainage holes to see if there are any leaves or small animal carcasses stuck. After cleaning, I will spray a specialized mold remover on the air conditioning vents. If the carpet is wet, it should be dried thoroughly to avoid mold stains. In severe cases, I will remove the seats for a thorough cleaning. I will also test the and air conditioning system to ensure they function properly. Regularly removing all trash before closing the windows can reduce the likelihood of this happening.

I prefer eco-friendly methods to tackle car odors. For instance, placing lemon slices on the dashboard for a few days to naturally absorb odors, or using a vinegar-water solution to wipe down the interior for disinfection. The top priority is identifying the source of decay: thoroughly inspect the seats, trunk, and AC components, and remove any foreign objects. Turning the heater to maximum to blow out the AC system helps eliminate mold. Regularly opening windows for ventilation is crucial to prevent moisture from breeding bacteria. Avoid masking odors with chemical fragrances; instead, focus on prevention by keeping the car dry and free of food residue.


