Is there anything better than the smell of a new car? It’s a gorgeous sensation that we all wish we could keep perpetually in our car. Unfortunately, odors tend to find their way into our vehicles, one common example being that of a distinct vinegar smell. Now, in the right context such as when eating Chinese dumplings or a nice plate of sushi, vinegar is a welcome addition to the party, but not when we get into our car to run errands or embark on a long journey.

What is causing this vinegar smell? We’ll be exploring this core question in today’s blog, as well as looking at what to do about it, and how you can prevent other odors from happening again in the future.

Vinegar Smell in Car – What’s Causing It?

Mold/Mildew in the A/C Ducts

Amazing as it may seem, there are many possible causes of that vinegar smell in your car. The most likely culprit is your air conditioning system. The build up of condensation in the a/c unit — especially if you live in a warm and humid climate such as Florida — can get to the point of excess where even the drainage system is unable to handle all of it. When this inevitably leaves your vents with excess moisture, what follows is the growth of mold and mildew. As these life forms rapidly move through their life cycle, they create new cells while others die off and decay, and the decomposure causes alcohol-like substances to be produced, which in turn is the source of the vinegary smell.

Your a/c system might not have any major faults if the climate you live in is conducive to these damp conditions, but more often than not the resulting mildew/mold growth is primarily caused by a technical fault in the a/c system such as clogged condensate pan, an ozone leak, or faulty condensate drainage system. Once the mold is in there, however, it will be a self-perpetuating problem as the organisms produce further condensation and moisture, causing the issue to spread.

While this is by far the most common cause of the problem, there are other possible things you can look at as well.

Dirty Air Filter

When was the last time you changed your car’s air filter? Air filters need to be cleaned or replaced regularly to prevent them becoming covered in musty debris, the smells from which inevitably end up in your passenger cabin. Similar to the a/c system issue, a hot and humid climate will exacerbate these issues with air filters.

Moldy Evaporator Coils

Does your car often go idle in the garage for long periods of time? Perhaps since the COVID-19 pandemic you have one vehicle that only gets taken out 20 minutes a week purely to keep the 12-volt battery alive. Long periods of disuse affect other components too, such as your evaporator coils and fins on your air conditioning system. Idleness tends to allow moisture, dirt, dust and other contaminants to gather on them, which then makes them into a natural breeding ground for mold, which as we’ve explained above is a big source of the vinegar smell.

Fungal Growth

Besides mold and mildew, your particular environment may also be conducive to the spread of fungal growth. Is your car parked close to places where fungi are growing? If so, their spores might find their way into your internal systems and lead to fungal growth there.

How to Isolate and Treat the Vinegar Smell in Your Car

The issues of mold or mildew in the air conditioning system is the most likely cause of the smell, so start by spraying your vents with special HVAC antifungal spray products first to see if that makes a difference. If that removes the problem and it stays away, then you’ve got to the bottom of it. However, should the smell return after initially going away, it suggests that there’s something wrong with one of the a/c components as we described further above. In this case, taking the car to a mechanic to get the a/c serviced and repaired is the best solution. They’ll likely throw in a more comprehensive a/c cleaning for you, too.

What about if you fix up the a/c and spray the vents but the smell is still there?

• Change your air filters. With a bit of confidence and the right components and tools, this is actually fairly easy to do yourself. The main thing to watch out for is getting the air filter in the correct way. Use directions on your specific product and make use of “how-to” DIY videos on YouTube to help. It’s best to find someone changing a filter in the same car that you have, if possible.

You can check out a range of air filters here

• Check your EV motor(s). If you’ve made the switch to an electric car, then you should know that your electric motors can sometimes leak ozone, which is getting into your a/c system and thus into your passenger cabin. So, if after clearing out the a/c system and changing air filters the vinegar smell is still there, you should consider the electric motors on your EV.

Step to Take to Prevent Future Bad Odors in Your Car

Vinegar smells aren’t the only bad smells that exist in our cars. Another common one, for example, is the smell of sulfur which manifests like rotten eggs, and is caused by leaking battery acid or problems in the fuel filter or injection system. Here are some steps to take to prevent any kind of rotten or unpleasant smell in your car:

Regular Maintenance and Servicing – Especially the A/C

As you can see from our information above, many of the sources of bad smells in your car are problems with various components like the air conditioning system, battery, fuel injection system, EV motors and other components. That being said, it’s critical that your car receives at least one good annual service where all these things are checked. Since the a/c is the most common source of these smells, we recommend you draw special attention to servicing that.

Regular Cleaning or Detailing

Another good way to keep smells away is by keeping your car as clean as possible. Washing it and cleaning the interior once a week at least is the best way to keep smells at bay. Levelling up to a full car detailing costs more money, but detailers will take steps to clean out your vents, carpets, upholstery and other areas your ordinary washing plan might miss. This is key to keeping bad smells away.

Good Habits

Two very good habits to keep your car smelling lovely: first is not smoking in your car and/or not allowing others to smoke in your car. Smoke gets embedded into the upholstery, carpets and roof liner very easily and can be devilishly tricky to remove. Solve the problem at its source.

The second good habit is you and your regular passengers — like family members — all taking it upon yourselves to take out at least 2 pieces of trash with them every time they leave the car. This prevents a constant buildup of trash, which can often get lodged in dark corners and stink the place out.

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