How to get rid of that foul odor from your A/C vents?

What is that smell?!

Have you found yourself starting up your car and smelling that awful smell from your vents? its very common and is more prevelant in certain climates throughout the world. Its not only an issue that arises in older vehicles, unfortunetley it can happen to newer vehicles as well.

So What is Causing This?

its actually quite simple; As your blower fan blows air from outside the car through your vehicles evaporative coil it is doing a few things. It is cooling the air that passes through the A/C evaporator, it is also removing moisture from the air. When your A/C is on, it creates an immense amount of condensation which you can see creates puddles under your car when the car is standing still(this is normal). Even when your A/C is not turned on to cool the air and maybe you have your heat on, the A/C compressor can still be running in the background to remove moisture from the air flowing through your vents. If you think about how many times a day you use your car and the period between those uses then you can imagine that moisture not drying quick enough on the evaporator. The moisture that sits on that evaporator for hours can turn to mold and bacteria which can cause that smell. Auto manufacturer's have even programmed in safety measures to help circumvent this issue, as its happening to newer cars still under warranty in certain climates throughout the world. A pretty smart feature that was programmed into vehicles as part of an update was to have the blower fan run after 10-15 minutes after the car is shut off on its lowest speed to try to dry out the evaporator quicker so it doesn't have time to have bacteria grow. This works great and doesn't drain your battery down too much between car starts, but not all cars have this feature and even when this is implemented the conditions can be so fierce that mold and bacteria still grow and you get that foul smell from your vents.

So what can be done?

Well, you need to get rid of the bacteria and mold on the evaporator which is harder than it sounds. You can take your car in for service to a dealership or service center that you take you vehicle to for service and they will most likely offer a package that will replace your dust filter and perform a foam cleanse to your evaporator which is fairly expensive. This operation is the only way to fix this issue aside from replacing your entire evaporator which would cost $1000's. Because your evaporator is smack-dab in the middle of your dashbaord its not easy to access and clean properly. If you follow the steps to complete the operation, you can DIY and enjoy the journey of working on your own vehicle and learn a new task(Bragable for sure!).

Can I just flush it with lysol?

I've seen videos out there on the interwebs that scare me! please don't try to flush out your AIR vents with LIQUID! if you attempt to spray tons of lysol cleaner down the intake where the filters sit you will most likely short out your blower motor because liquid and electrical components don't do well together. Its not a good idea, trust me, i've replaced plenty of blower motors because someone wanted to save 30 min and try to take a short cut.

A Professional Product is in need!

There are a lot of products available to consumers and some are only available to automotive service centers through contracts they hold with these products. The best one available that is also professional grade is the DWD2 Clean Air. I like that its unscented so you don't have this punget interior that is hard to sit in for several days and I like that they've been around for years with tried and test products.

How to DIY

I'll lay the basic steps out for you to be successful, but you always want to follow the guide that comes with this kit as well as refer to thier tutorial videos which i've placed below for your convience.

1. Change into some cloths you don't mind getting a little dirty or dusty. Get a pair of Rubber gloves(latex disposible and I provided a link to a get pair below).

2. You want to approach a task like this with patience. If you try to rush or are short on time to do this task your going to stress yourself out and that can cause unnessary errors. You want to be patient with your car, because a lot of the items you need to R&R(remove and replace) require patience to get out properly without breaking something. Not to mention they can have sharp edges and corner and can cut the crap out of your hands if your not paying attention.

3. Go to the passenger side of your vehicle and find the under dash panel. some vehicles may not have a panel, which then you might just see the blower fan and ducting. Some vehicles require the glove box to be removed, which is usually just two tabs that release it. What you are looking for is the plastic ducting between your blower fan and your a/c evaporator and heater housing( pictured in the illustration video below).

4. You want to drill a 3/16 hole to insert the injection nozzle. The reason behind this: you want to inject the foam after the blower motor and before the a/c evaporator. WARNING! You want to be very careful and make sure you are not drilling into the blower motor area or the a/c evaporator. If you drill into the evaporator that will be the end of it and you'll need to have your evaporator replaced. You just need to be sure you've found the area between the two which is illustrated in the video below. The video also gives you a good idea of what is behind the dash that you can't see.

5. Once you drilled that hole then you can insert the injection tip into the tube provided and follow the instructions(usually they want you to shake up the can a bit or inject the foam with the can sideways) on how to prepare the can before use. Then simply put the injection tip into the hole you drill.

6. Turn the vehicle on and turn on the a/c to full blast and turn on the recirculation button if your vehicle has it.

7. Start inject the foam for about 30 seconds and see if you can hear a difference in the airflow. You should start to smell clean fresh scent at this point. start to inject more foam. If you see foam come out of the two front and center vents or even small particles of foam spitting out you are doing good. this means the foam has mad its way into the housing and is saturating the evaporator.

8. You want to turn everything off after you know there is foam in the evaporator housing(use a flashlight to see if you can look straight down the front and center vents to see if you see foam). Let the vehicle sit for 15 mins completely turned off to let the foam do its job. at this point you will see a lof of foam dripping throught he drain tubes on the ground below the vehicle. This is norm and means the foam is turning to liquid.

9. After 15 mins of letting the vehicle sit, you can start it up agian and blow out any residuel foam left in the evaporator housing. If its coming out the vents like its snowing, then you can wait a bit longer as its probably not the best to get on pleather/leather seats.

10. Once you have finished that step you can remove hte injection insert and plug the whole that was provided in the kit and careully re-install the under dash panel and "Voila" its done! at this point its time to inspect your dust filter and replace if they smell or have a lot of dust or dirt.

If you are stuck and have a vehicle that doesn't fit in this description and you have the kit please reach out to the team and we can help do some research to make sure you complete the task.

Thanks,

Philip B