Car AC Smells like Vinegar: Causes & Fix Solution

(Last Updated On: March 14, 2024)

Does the smell of vinegar from your AC pose a risk? Moreover, what could be the source of this odor in your vehicle?

Vinegar smell is not dangerous, it may be caused by mold build up in car ac, natural decaying material, or bad air conditioner filter, so on.

Read this article to the end to know why and how to get rid of vinegar smell in car.

4 Causes Car AC Smell Like Vinegar and What To Do

Some car owners assume that the sour odor coming through the air conditioning vents results from vinegar. However, that isn’t usually the case. We have described four possible causes in this section.

1. Mold/mildew buildup

Two of the typical culprits are mold and mildew. They can form in the vents of your car and are caused by several factors such as moisture, dirt, dust, and leaves that accumulate in the vents over time.

Prolonged periods of vehicle disuse can cause these agents to collect on the evaporator fins and coil. AC systems produce condensation, which can be sufficient enough to cause mold or mildew to grow if it doesn’t dry totally.

What to do?

It is best to let an expert in car mold and mildew removal handle the inspection and cleaning because of the health hazards, especially cabin air pollution by mold spores.

However, you can handle the decontamination independently if you have the right cleaning equipment, protective gear (e.g. gloves and nose masks), and enough experience. Take the following steps:

  • Step 1: Get a Disinfectant

Buy a disinfectant aerosol spray that can kill mold and mildew, such as Lysol. It is best to use a specialty spray (e.g. specialty duct cleaner). You can also use an EPA-approved, hospital-grade disinfectant that can wipe out every trace of the two odor-causing agents.

  • Step 2: Ensure that the AC, Fan, and the Car Are Switched off

You need to do these before applying disinfectant into the vents.

  • Step 3: Apply the Disinfectant

Spray the disinfectant into all the vents, including the ones at the driver’s seat, passenger seat, backseat, dashboard, and rear windshield. Make sure every door is closed during this step.

  • Step 4: Put Car, AC, and Fan on

Make sure the AC and fan are working at full power so that the air with the disinfectant is well-circulated around the AC system.

  • Step 5: Spray the Disinfectant into the Re-Circulation Vent

Check your car’s manual for the location of the re-circulation vent. It can be near the console, on the driver’s side floor, or in the trunk. Press the vent’s little button (with arrows indicating a circle) if the vehicle has it. This action will make your car stop taking air from outside and recycle the internal air. It would be best to spray the disinfectant into the vent while the AC is still running.

  • Step 6: Switch to Full Fan Mode

This step involves switching the AC from “max” to full fan mode to avoid cooling the air further. You would want to be blowing ordinary air instead.

  • Step 7: Lift the Hood, Change the Cabin Air Filter, and Apply Disinfectant to all the Intake Lines

These are done for serious mold/mildew buildup situations.

  • Step 8: Open the Doors, Run the Vehicle, Switch the AC off, and Let the Fans Work at Full Power

This is the last step in drying out the system. The fans should operate at full power for 5 minutes.

  • Step 9: Take Preventive Measures

Get the air conditioner checked and cleaned periodically.

Moisture or water vapor content in cars should be tackled with a dehumidifier.

Condensation can be reduced by sealing leaky areas with EPA-approved sealants, cleaning the drip pans regularly, and insulating the air ducts.

You can also use the fan to dry out the air conditioning system. Do this by switching the AC off and then leaving the fan open on high for about 10 minutes. Carry out the task before turning the vehicle’s engine off or parking. Some carmakers have included the After-Blow functionality in their recent models to perform this operation automatically.

The cause of that acidic smell might be a buildup of natural material decaying in or around the vehicle’s vents or AC. Accumulated plant or animal matter can decompose, ferment, and turn into alcohol with the aid of water droplets formed in the HVAC system. It will then become somewhat sour and start giving off a vinegary stink. The AC will blow the stench into the cabin. Look out for decaying dead animals or plants, food leftovers, or other organic materials.

2. Natural Decaying Food

The cause of that acidic smell might be a buildup of natural material decaying in or around the vehicle’s vents or AC. Accumulated plant can decompose, ferment, and turn into alcohol with the aid of water droplets formed in the HVAC system. It will then become somewhat sour .The AC will blow the stench into the cabin.

What to do?

The great journey will lessen when the matter has decayed well enough. But you can’t leave it untouched, can you? Wear your gloves, and nose masks, then follow the steps outlined below to get rid of the source of the smell.

  • Step 1: Use a vacuum cleaner to clean out the vents.
  • Step 2: Remove the vents to check for the decaying material if vacuuming doesn’t work. It could be animal remains, dead plant matter, or debris.
  • Step 3: Get rid of any accumulation of dead matter.
  • Step 4: Clean the affected area with foam paint brushes and detergent.
  • Step 5: Spray the vents with disinfectant.
  • Step 6: Put on the AC and fan while the doors are closed to make the air circulate.
  • Step 7: Let the car air out after some time for as long as possible.
  • Step 8: Apply air freshener into the ducts to eliminate traces of the odor.

Read more: How To Vacuum Car AC System Without Pump

3. Emitting Ozone in Electric Air Conditioner Motor

A car’s AC lets ozone emissions into the cabin because it uses the air outside. Deodorizing or cleaning your vehicle with ozone shock treatments (utilizing an ozone generator) can also cause the scent to linger for days.

Ozone produced by an electric AC motor in an EV (electric vehicle) can have a sour smell, especially in combination with other possible sources of vinegar-like odor. It may also be a pleasant scent. ICE (internal combustion engine) vehicles (diesel, gasoline, and LPG, gasoline) can also emit ozone. Please don’t be tempted to keep enjoying the smell because too much of it can harm one’s health. Ozone at ground level is toxic to humans, animals, and the environment.

What to do?

Getting rid of this smell is simple with the steps below.

  • Step 1: Air out Your Car

Keep the windows open for a few hours. Should do it daily until the scent is no longer noticeable. You will stop smelling ozone after a few days.

  • Step 2: Drive Around for Some Minutes

Take the car for a drive each day with the windows open. Doing this will make the method more effective and yield quicker results.

4. Bad Air Conditioner Filter

A defective AC filter is another common cause of “vinegary” scents in a car’s cabin. Moisture accumulates in the filters and combines with dust and debris. This can be severe for those that use their ACs often or live in locations that have a hot, humid climate. Watch out for a clogged, dirty, or damaged AC filter. Air filters can easily get dirtied by dust or debris.

What to do?

You would need to get the filter replaced if the cause of the vinegar-like smell is a bad AC filter. It is recommended that you clean the drain lines and tubes before changing the cabin filter. Ensure they are in good condition too. Drain lines are located near the condenser unit. They would need to be cleaned with industrial-grade gear. Now read the following five steps to change your AC filter:

  • Step 1: Buy a new high-quality air filter.
  • Step 2: Look for the cabin air filter compartment. This may be difficult to find, so check your car’s manual. It is typical somewhere in or underneath the dashboard—maybe behind the glove box. You may find it in the engine bay, but be careful not to mistake it for the engine air filter. You may need tools to remove some knobs before reaching the compartment.
  • Step 3: Open the air filter compartment. You will find the old filter underneath or behind the cover.
  • Step 4: Remove the old air filter with a safety glove.
  • Step 5: Clean out the compartment with a wiping cloth, rag, or vacuum cleaner.
  • Step 6: Slide in the new filter carefully. Make it face the same direction the previous one did.
  • Step 7: Close the air filter compartment and put everything other back the way they were.

Read more: Why Is My Car AC Making Hissing Noise?

Leave a Comment

Your email address will not be published. Required fields are marked *