If you don't change your cabin air filter, the filter will become clogged with dirt and debris, compromising the efficiency of your car's filter and HVAC system. This will reduce the volume of air in the passenger compartment, causing bad odors to appear inside your car. Additionally, dust will accumulate on the filter, leading to strange high-pitched groans behind the dashboard and louder air conditioning system sounds. Mold can also build up on the filter, which is extremely unhealthy to inhale and can cause serious illness.
By replacing your cabin air filter regularly, you can avoid breathing in unhealthy mold and keep your cabin smelling fresh. If you notice that your air conditioning system is sounding louder than usual, it could be a sign that your cabin air filter needs replacement. Dirty or excessively clogged cabin air filters can produce a dusty and damp odor when the HVAC system is turned on. Replacing the filter regularly ensures that pollution stays outside your vehicle, allowing you to breathe healthier air inside.
While there's no direct impact on engine performance with a broken or malfunctioning cabin air filter, it's not recommended to do so. This condition suggests that you may have an allergic reaction to air coming out of the air conditioner. During high pollen seasons, pollen and other allergens can build up in the filter, so it may need to be changed more often.Today, many brands sell cabin air filters with the idea that no one wants to spend time in a smelly car if they can help it. Some mechanics will recommend that you change the cabin air filter during your routine garage visit for regular maintenance.
This is likely because they understand the real dangers of not changing it, partly due to how cabin air filters have been marketed.