How to deodorize a car A/C system

Updated April 17, 2017

Bad odours in a car can be a sign of engine problems. Odours that are trapped within a car's air-conditioning system can be hard to do away with. Some common types of odours are caused by cigarettes, stale food and dampness within the carpet or upholstery. Offensive odours can be removed by following a regular maintenance routine.

Gather cleaning materials. Park your vehicle in a shady and well-ventilated location.

Clean out the interior of the vehicle by discarding piled-up trash. Wipe up spills using paper towels.

Brush the upholstery carefully. Vacuum the inside of the vehicle.

Open the car doors and windows to allow the car to aerate. Turn on the vehicle.

Raise the hood of the car. Turn on the air-conditioning unit to the highest setting.

Modify the air-conditioning unit to allow outside air into the car. Find the cowl vent within the engine compartment, usually on the passenger's side below the windshield.

Spray deodoriser directly onto the cowl vent screen. Wait for a few minutes to allow the deodoriser to circulate through the air-conditioning unit. Turn off the air conditioning.

Turn on the heater using the highest settings. Spray the deodoriser into the cowl vent again. Use the car refresher to keep offensive odours away.


Keep a bag of charcoal briskets to absorb offensive odours within your car. Wipe up spills immediately with paper towels to keep odours at bay.


Sweet smells coming into your cars air-conditioning unit might be a sign of engine overheating. Have your car serviced immediately when you notice these types of smells.

Things You'll Need

  • Carpet/upholstery brush
  • Car vacuum cleaner
  • Paper towels
  • Car refresher
  • Deodorising spray
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About the Author

Leah Logan was born in East Palo Alto, Calif., and currently resides in Austin, Texas. She is an international author, certified diversity consultant and the founder and president of The Purple Heart Institute, a consulting and coaching business for self-esteem, transition, recovery and empowerment.