Why Does My Car Air Conditioner Smell When I Turn It On? — Openbay Overdrive
It could be a few days, a week, or even a month before you finally get behind the wheel of your car. It’s hot outside. You start your car, turn on the air conditioner (AC), and then an unpleasant odor takes over the cabin.
For starters, let’s hope you are alone when this event occurs and not on any first date. An unpleasant smell in any environment could turn into an embarrassing moment for not only you but your passengers.
Any Odor is The Car’s Voice Telling You It Has a Problem
There is nothing less inviting than getting hit by a wall of ‘stink’ when you turn on your car’s AC system. Some refer to the odor as “dirty and sweaty socks”, “musty”, “rotten eggs”, “mildewy”, and “burnt plastic” to call out a few. What could be the root cause of the odor and how can we get it to go away? Before we get into what could be the cause, it’s important not to ignore the smell. And the smell will not go away on its own.
There are a number of causes for odor emanating from a car’s AC system. Let’s go over a few tips on what to do about it and prevent the smell from coming back.
Change Your Cabin Air Filter
This is typically the main cause for most odors coming from a car’s AC system. A best practice is to change your car’s cabin air filter(s) one every 30,000 miles or so. AC systems tend to hold moisture from condensation — this is when mildew and mold can build up on the filter itself causing a very nasty odor when the fan is turned on. The Cabin Air Filter is a filter that sits between the outside of the vehicle and the passenger cabin. It filters outside air before it enters the cabin removing dust, small airborne particles, and pollutants. Each of these can collect and stay present on the filter.
Cabin air filters are easy to replace, but if you are not comfortable replacing the Cabin Air Filter, have a local service technician replace one for you. Openbay can help you find a local professional to perform the service. The total cost to replace a Cabin Air Filter can average $35-$80 depending upon the vehicle when installed by a shop.
Here are some example costs of a cabin air filter installed by a professional technician. Pricing includes parts and labor:
2011 Honda Accord: $40.00 — $45.00
2011 Toyota Camry: $55.00 — $65.00
2010 Nissan Altima: $45.00 — $55.00
2002 BMW M5: $120.00 — $140.00
Clean Your Vehicle Air Ducts to Get Rid of Mold, Mildew and Bacteria
AC systems contain a fair amount of moisture. With any moisture rich environment, mold, mildew and bacteria can build up. This can be another source contributing to odor in the vehicle’s cabin. When a Cabin Air Filter is properly installed and maintained, the result is the build up of mold, mildew and bacteria. A typical vent cleaning service (removes bacteria within the vent system) can cost upwards of $200. If you decide to do-it-yourself, there are many home solutions that can be used to clean out the vent system. It just takes a fair amount of manual labor, a rag and a small bucket of diluted bleach or simple-green type of product.
While cleaning out the vent system, making sure the evaporator drain hose is clean and free to allow the AC system to drain properly.
Keep the Drain Clear
The job of the car’s AC system is to remove heat and moisture from inside the cabin — the air surrounding the passengers and driver. Various system components are involved in condensing the moisture and then channeling it to exit the vehicle in the form of water via a drain line. If the drain line gets clogged or is leaking, this could be another cause for mold and bacteria to build up.
Is there evidence of a Fuel or Fluid Leak
Let’s begin with the smell of fuel. If you smell fuel while your vehicle is either running or not, turn off the engine right away. And certainly do not drive it anywhere. Have it towed to a local shop to have a professional technician have a look at the vehicle. Even a small fuel leak can cause vapors to ignite, causing serious injury.
A Sweet Odor is Not Good
If the smell is of a sharp, sugary-type smell, you are most likely leaking coolant. Coolant can leak from several parts of the HVAC system. Best to have a professional have a look at the system. This is a service not for the do-it-yourselfer. The system needs to be pressure tested to find the leak/s and repair or replace any necessary components.
If you need a trusted technician to look at your vehicle, give Openbay a try. Openbay is an online marketplace for automotive service and repair. Openbay has helped my car owners get their AC system fixed and their odor is no longer present.
Originally published at https://blog.openbay.com on September 1, 2020.
