Car AC Smells Like Vinegar: Why and How To Fix Immediately?

Does your car air conditioner smells like vinegar but you don’t know why and how to get rid of it ?

There are some reasons cause car ac smells like vinegar you should consider such as moisture in car air conditioner, foods, voltage regulator or catalytic converter.

Whether your car ac smells bad when first turned on or it happens all the time, you’re in the right place!

This article will tell you why, how to get rid of vinegar smell in car ac as well as how you can prevent the smell in the future.

Is Car AC Smells Like Vinegar Dangerous?

In general, if the vinegar smell is strong, it could be a sign of a problem with the car’s air conditioning system. However, it is not always dangerous to drive with a car that smells like vinegar. If the smell is mild, it is probably nothing to worry about. However, if the scent is strong, it is best to have the car checked out to avoid serious problems.

Why Does My Car AC Smell Like Vinegar?

moisture, food, voltage regulator overcharged, clogged battery can cause vinegar smell in car ac.

1. Moisture and Mold Build Up In Car’s AC

Usually, when you turn on your car, there is always hot air outside, and cold air gets generated by the air conditioner unit. When heat exchange happens, the cold air runs through the air conditioner. Hot air also flows through the unit, resulting in a condensation process that leaves moisture in the A/C unit. The moisture then leads to the growth of bacteria and mold build-up. As the mold decays, fermentation occurs, leading to alcohol formation, forming a vinegar-like smell. This is why your car smells like vinegar as soon as you turn on your air conditioner.

How to fix?

Before you can begin, ensure you have a car air conditioner cleaner.

1. Start the car and turn both the a/c and the fan to the maximum. Open all the windows and the hood to access the fresh air intake vents located by the windshield.

2. Spray the air condition cleaner for about 5-1- seconds right into the fresh air intake vents and turn off the car immediately you’re done. This allows the cleaner to stay in the core and not get vented off.

Moisture is in car air conditioner can cause vinegar smell in car.
Spray the car air condition cleaner into car air vents.

3. Keep the fan and the a/c off for around 4-6 hours. Performing this task overnight is recommended.

4. When you turn your car back on, open all the windows and turn the fan to the maximum. This helps to get rid of bacteria and mold that got killed.

Note: If you’re still smelling a bad odor in your car after cleaning the ac, you may need to replace the cabin air filters.

The function of the cabin air filter is to trap smells and dirt that are trying to get into the car. Once the filter gets old, they start producing a vinegar smell in car. If this is the case, you will need to buy and replace the old air filters with the new ones.

When shopping for cabin air filters, look for antibacterial and antifungal air filters. These are the ones that help your car smell the best and eliminate odors.

2. Food Left Somewhere In Your Car

You can also forget food in your car for a long time that it rots in the car. This can cause car ac smells like vinegar that is so unpleasant to many.

Forget foods in cars for a long time can  cause ac smells like vinegar.
Forget foods in cars for a long time can cause ac smells like vinegar.

How to fix?

These steps can help you get vinegar smell out of car ac totally.

1. The first step is to eliminate the source of the smell. You will have to go through your car and find the food. Check underneath the seats, the floor, trunk, cargo nets, and other storage spaces in your car. Wear your gloves while removing the food and when cleaning because it could get glossy.

2. Even though it may not seem to have a smell, clean the inside windows with some glass cleaner, wipe down the dash and the plastic panel using some interior cleaner.

3. If the food was in the carpet, vacuum it up to remove the debris and dirt then using a carpet shampoo. 

4. If the food or drink spilled over into the seats , you would need to use an upholstery cleaner or a carpet shampoo. Scrub the areas until they are clean.

5. If the odor persists, sprinkle baking soda on the area and allow a few hours to absorb the smell. Afterward, vacuum the powder. The smell should disappear.

Note: Besides using an interior cleaner to clean food in car, you should use an anti-bacterial spray to eliminate odor. In this way, you can protect yourself and your family from mold and bacterial.

3. The Voltage Regulator Overcharge the Battery

A voltage regulator maintains the correct spark levels of the alternator. If it becomes faulty, the alternator overcharges the battery, leading to the gradual bubbling of the battery acid. So, you will sense the vinegar smell in car. 

the alternator overcharges the battery leading to the gradual bubbling of the battery acid. This causes vinegar smell in your car.

How to fix?

If this is the case, clean the acid or replace the faulty voltage regulator in your car with these steps.

1. Locate the voltage regulator under the hood of the car. In most cases, the voltage regulator is on the back of the alternator or the inside. Only in rare cases will you find it on the sides.

2. Use a wrench to detach the battery cables, beginning with the positive cable labeled with a ‘+’ sign. 

3. Position the new regulator over the faulty one in line with the cables, without attaching it to the alternator. Remove each cable from the old regulator and plug it into the new one. You may find up to four cables, depending on the model of your car. 

4. Replace the battery cables and tighten them with a wrench, ensuring you attach them in the right way; positive charge to positive and negative to negative.

Note: You can let professionals replace the voltage regulator

Depending on the type of car you own, replacing a voltage regulator could mean replacing the entire regulator or just the voltage regulator. If you are replacing the whole alternator, it should cost between $200 and $500. If it’s just the voltage regulator, it costs between $20 and $200. The labor cost is estimated between $50 and $100.

4. A Clogged Catalytic Converter

Why catalytic converter?

Because cars are just like human beings. They, too, have to breathe in, so ensure you have clean filters. But they also have to breathe out through the tailpipe. If the exhaust system is clogged up, in most cases, the catalytic converter, the engine suffocates and cannot exhale. This causes the vinegar smell in your car due to the formation of gases.

See also: Can We Clean Catalytic Converter With Lacquer Thinner?

Clogged catalytic converter may cause the vinegar smell in car.
Clogged catalytic converter may cause the vinegar smell in car.

How to fix?

Follow below simple steps to solve this problem:

1. Since the catalytic converter is located at the rear bottom side of the vehicle, you will have to jerk it up to see it better.

2. Drill two holes in front and behind the catalytic converter to measure the exhaust pressure with a gauge. (remember to close the holes once done checking). Stick the gauge in the holes one at a time, turn on the engine, and measure the pressure.

3. If the pressure at the back is less than 1 pound (lying in the green area of the gauge), and the pressure at the hole behind the catalytic converter is way beyond the green line, it means the catalytic converter is clogged.

4. You will need to make it clean or replace your catalytic converter with a new one.

So, I have given you four ways to eliminate the vinegar smell in your car. However, you also should know how to avoid them.

How To Get Rid Of Vinegar Smell Immediately?

If you’ve ever experienced an ac in a car that smells like vinegar, you know how unpleasant it can be.

Not only is the odor incredibly strong, but it can also be quite challenging to get rid of. If you’re looking for a car AC odor eliminator that will effectively eliminate the vinegar smell from your car, I recommend using the below products:

Meguiar's G16402 Whole Car Air Re-Fresher Odor Eliminator

Meguiar’s G16402 Whole Car Air Re-Fresher Odor Eliminator

Armor All Car Air Freshener and Cleaner - Odor Eliminator

Armor All Car Air Freshener and Cleaner – Odor Eliminator

Lubegard 96030 Kool-It Evaporator and Heater Foam Cleaner

Lubegard 96030 Kool-It Evaporator and Heater Foam Cleaner

InterDynamics Certified A/C Pro Vent and Duct Cleaner, Professional Strength Odor Eliminator

InterDynamics Professional Strength Odor Eliminator

How To Avoid My Car AC Smells Like Vinegar?

Prevention is always better than waiting to find a solution. These car care tips will help you forget about having a vinegar smell in your car again.

1. Hang an air freshener in your car. It will help add a fresh smell to your interior. Air fresheners work by masking and odors, not by eliminating them. Therefore, you will need to use other tips to prevent the smell.

2. Ensure you clean spills and remove food particles from your car and never let them rot. A good way is to have a bin to keep leftover food and dirt. It would be best if you never forgot to clean the container regularly.

3. Replace your air filters more often if they have been there for long. We recommend using antifungal and antibacterial air filters.

4. If your car has over 70,000 mileage, consider replacing it with a new catalytic converter before the old one gets clogged out.

5. Often check the voltage regulator and ensure it’s not overcharging the battery.

6. Leave your car windows open to get rid of odors.


1. How often do you change the air filter in your car?

You should change the air filter of the car after 15,000-30,000 miles. This, however, depends on the driving conditions.

2. Can I change my car air filter by myself?

Yes. Replacing your car’s air filter is really fast and under 20 minutes and typically doesn’t require any tools.

3. Can you clean and reuse car air filters?

Although you can clean and reuse car air filters, you will need to replace them at the next service. 

Read more:

Gas Smell In Car: Causes And How To Fix

4 Quick Tips to Get Weed Smell Out of Cars?

Car Smells Like Rotten Eggs

1 thought on “Car AC Smells Like Vinegar: Why and How To Fix Immediately?”

  1. Pembroke Pines Fl

    Prevention is always preferable to waiting for a solution. These car care tips will help you never smell vinegar in your car again. Thank you!

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