Car AC smells like vinegar: Why and how to fix it


What do I do if my car’s AC smells like vinegar?

The car’s air conditioner may make the odor stronger. To determine if the smell persists, turn off the AC unit. If the smell does not stop after turning the unit off, checking the AC vent could be an option. Check twice by driving without the AC on.

In such a situation, the first thing you should do is decide whether to visit an auto shop. You can determine the root cause of the vinegary smell and the severity of the problem on your own. If you are unable to find the cause, it is worth calling a technician or mechanic to inspect the AC.

If you have the DIY knowledge or experience, then you can tackle the problem. Hire a professional immediately if you don’t have the necessary knowledge or experience. The expert will investigate the problem and take precautionary measures to address the issue without making the car a danger to your health.

The top 4 reasons and how to eliminate the vinegar smell

Many car owners believe that vinegar is the cause of the sour smell coming from the air conditioner vents. This is not usually true. In this section, we have listed four possible causes.

These are 4 reasons why your car smells like vinegar.

Mold/mildew buildup

Mold and mildew are two of the most common culprits. These can form in your car’s vents and are caused by many factors like moisture, dirt, and leaves that build up over time.

These agents can build up on the coil and fins of your evaporator coil if you have a long period of vehicle disuse. AC systems can produce condensation that can cause mold growth if it isn’t dried completely.

If the AC needs to be changed frequently, if the AC is not working as it should, or if the battery drains unusually, then the AC should be checked. These signs could indicate mold growth or mildew accumulation (or a combination of both).

There are two types of fungus: mold and mildew. The technician may say there is fungus in the vents. It could be one of these or both. A study of fungal colonization in automobile air conditioning systems revealed that Penicillium and Alternaria are the most common fungi species that can cause damage to automobiles.

You can identify mold by its flat appearance or fuzzy appearance with moist, slimy or powdery forms. Its color can be yellow, blue, brown, gray or white. Black mold is one type that car owners should be aware of if they find it on any surface. Mildew, on the other hand, has a flat growth that can appear powdery and fluffy. The initial colors of mildew are white, yellow, and gray. These colors will eventually turn to black or brown.

How do I fix

It is easy to see that the two organisms can be confused for one another. However, it is important to not take either one of them for granted. Because of the potential health risks, it is better to have an expert in car mold removal and mildew cleaning inspect and clean the cabin.

You can decontaminate your own home with the right equipment and protective gear (e.g. gloves, and the necessary experience. Follow these steps:

There are nine steps to deal with mold buildup.

  • Step 1: Get a Disinfectant

Lysol is a disinfectant spray that kills mold and mildew. A specialty spray, such as Lysol, is better. A specialty spray (e.g., specialty duct cleaner) is best. An EPA-approved hospital-grade disinfectant can also be used to eliminate any trace of these odor-causing agents.

  • Step 2 – Ensure that the AC and Fan are switched off

These steps should be completed before you apply disinfectant to the vents.

  • Step 3 – Apply the Disinfectant

Spray disinfectant all over the vents. This includes the ones located at the backseat, driver’s seat and dashboard. Ensure that all doors are closed during this step.

The location of the vent can be found in your vehicle’s manual. It could be located near the console, the driver’s side, or in your trunk. If the vent has one, press the button with the arrows that indicate a circle. The car will stop receiving air from the outside and start recycling its internal air. Spray the disinfectant in the vent while your AC is running.

Make sure to have your air conditioner cleaned every so often.

A dehumidifier should be used to combat moisture or water vapor in cars.

You can reduce condensation by sealing any leaky areas with EPA approved sealants, regularly cleaning the drip pans, and insulating your air ducts.

The fan can also be used to dry the air conditioner system. Turn the AC off, then turn the fan on high for approximately 10 minutes. Before parking the car or turning it off, complete the task. To perform this operation automatically, some carmakers have added the After-Blow function to their latest models.

Natural decaying matter

AC can be suffused with an acidic scent from natural decaying materials.

This acidic smell could be caused by a buildup of natural material that has been decaying around the AC or vents. With the help of water droplets in the HVAC system, accumulated animal or plant matter can be decomposed, fermented, and turned into alcohol. The AC will make the air smell vinegary and sour. The AC will then blow the smell into your cabin. You should be aware of dead or decaying plants and animals, as well as food leftovers or other organic material.

How do I fix

When the matter is sufficiently decomposed, the great journey will slow down. You can’t just leave it alone. Follow the steps below to eliminate the smell source.


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