When buying a used car, one of the biggest issues you’ll find is unwanted smells in the interior. Odors can be difficult to get rid of especially when the smell has essentially soaked into the fabric. You can try shampooing the fabric but this won’t always work as it may not be able to penetrate deep enough to get to the source of the odor.
This is where an ozone generator can help. An ozone generator will pump O3 into the car where it can saturate the fabric and other interior components and kill the bacteria creating the odor. Doing the shock treatment can get rid of human/pet odors, cigarette smoke, and even mildew smell from water damage.
For this job we will be running the engine for 30 minute increments so make sure the vehicle is outside where it can get plenty of fresh air. Make sure you also have enough gas so that the car doesn’t run out. The ozone generator is also set up outside the car so make sure the weather is good as we don’t want rain to damage the generator.
Part 1 of 1: Ozone shock treatment
Note: Ozone generators are expensive, but thankfully there are services available where you can rent one for a few days. They vary in how much ozone they can produce, but you want to get one that is rated for at least 3500 mg/h. 12,000 mg/h is the max that you would want to go for a typical passenger vehicle, any more is unnecessary. A good sweet spot is around 7000 mg/h. Smaller units may be able to be propped in the window or you can use a tube to direct the gas into the car.
Step 1: Prepare the car. For the ozone to do it’s job, the car needs to be completely cleaned out. The ozone can’t kill bacteria it can’t reach so make sure the seats are vacuumed and all hard surfaces wiped down thoroughly.
Make sure any papers in the glove box are removed and if your spare tire is located inside the car, be sure to take it out so nothing is affected by the ozone.
Pull the carpets up and set them up in the trunk so air can flow all around them.
Step 2: Set up the generator. Close all windows except for the drivers. Hold the generator at the top of the door frame and roll the window up to lock the generator in place. If your unit has a tube, just stick one end of the tube in the window and lock it in place by rolling the window up part way.
Step 3: Block off rest of open window. Use cardboard and make a cutout of the remaining window. We want to block the window so air from the outside doesn’t come in and disturb the ozone. Use duct tape to secure the cardboard and tube, if applicable.
Note: We don’t need the cardboard to block all the air just most of it. The ozone works best when it can soak inside the car and saturate everything. Fresh air coming in will push ozone out of the car and we don’t want that.
Tip: Painter’s tape doesn’t leave a residue and is easy to take off. We don’t need this to last long so save yourself some time in the end by using painter’s tape.
Step 4: Set fans to circulate cabin air. A little known fact about climate control is that you can control where the air comes from. You can get air from the outside or you can circulate the air inside the cabin.
For this job, we’ll set them to circulate the air around the cabin. This way the ozone will get sucked into the vents to clean them out. Set the fans to max speed as well.
Step 5: Start the engine and run the generator. We’ll run the generator for 30 minutes at a time. Set a timer and let the ozone start working.
- Warning: O3 is harmful to humans and animals so make sure no one goes near the car while running the generator. Also, some generators may have a high and a low output. Make sure it is set to the correct rating.
Step 6: The sniff test. After 30 minutes, turn the generator off and open all the doors to air the car out for a few minutes. There may be a small smell of ozone that will dissipate after a few days, but the smell should be gone or at least much better.
If the smell is still present, you can run the generator for another 30 minutes. If you have to do this more than 3 times however, you may want to get a higher rated generator.
- Note: Since O3 is heavier than air, smaller generators may not be powerful enough to push the ozone all the way up the tube into the car. If using a small unit with a hose, you can place the unit on top of the car so gravity will help push the O3 into the car as well. This can help make sure you are getting an adequate amount of ozone into the car.
With one or two 30 minute runs of the generator, your car should be smelling fresh as a daisy. If the results aren’t as inspected, there may be issue with liquid leaking causing the odor inside the vehicle so it should be inspected further to determine the source. As always, if you experience any issues or troubles with this job, our certified technicians are available to help you sniff out the problem.
This article originally appeared on YourMechanic.com as How to Get Rid of Unwanted Odors in Your Vehicle and was authored by Spencer Cates.