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Why My Car AC Stinks When Turned On?

On a hot summer day, you get into your car, the seats are hot and you crank up the AC. This is a one-of-a-kind feel but, this can make your mood go bad real quick. The car AC which is supposed to make us feel better can produce funky smells. Now you must be wondering “why does my car AC stink?”

A car AC stinking could have any reason. Most of the time, your AC will smell like fuel, rotten eggs or even mould. This makes your situation even worse as you have no idea what is causing this. But, you’re in luck as this article will tell you everything you need to know about this.

The driver turns on the air conditioning system in his car.

Why Does My Car AC Stink?

There could be many reasons for your AC to stink. The smell source could be either from inside the car or outside the car. If the smell is coming from outside the car, it is not a problem. If the smell source is from inside there could be something wrong with the AC. For your convenience, the most common causes are mentioned below-

1. Gas Leak:

This is a very common problem and if this is causing your AC to stink it will smell like fuel. The air filters could also be going bad. The gas leak is making the gas slip into the AC system. This smell will enter the cabin. A gas leak is very dangerous so make sure you turn off the engine and get your car towed to a repair shop. A gas leak can easily cause an explosion.

Man turning on car air conditioning system. Air conditioning button inside a car.

2. Fungus:

The smell of mould or mildew can be caused by fungal growth in your car. This happens mostly during monsoons, due to the excess moisture. Fungal growth is also promoted by dirty laundry in the car. If you have anything that can cause excess moisture in your car, you should remove it. After removing the source you should clean it using white vinegar and water. Also, make sure your car does not have any kind of leaks. A type of mould can also make your car smell like vinegar.

3. Battery Acid Leak:

A battery acid leak can cause your car to smell like sulfur. Ozone emissions can smell like vinegar. If you are smelling something similar it is best to rush to an automotive shop.

4. Faulty AC Compressor:

If you are smelling burning rubber, there is a high chance your AC compressor is not aligned properly which is making it drag. Henceforth, causing the burning rubber-like smell.

5. Electrical Issue:

An electrical issue can also cause your AC to stink. An electric short, burnt wire or excessive dust in the vents can cause the burning plastic smell. If there is a similar smell in your cabin, there is a high chance the components above are damaged or affected. In any case, you should get your car checked.

6. Oil Leak:

An oil leak can create a burning oil smell which is very unpleasant. This is a very serious problem and shouldn’t be ignored. An oil leak can easily catch fire and cause an explosion.

How To Get Rid Of AC Stink?

An AC stink can have many reasons and it is very hard to identify the cause behind this. It is best to leave it to the hands of professionals. You should head to a repair shop and get this fixed. There could be something wrong with your car and it needs to have a professional check.

Young woman holding her nose because of bad smell in car

How Much Would It Cost To Fix AC Stink?

The cost is going to depend from issue to issue and from vehicle to vehicle. If mould is causing the stink, you would basically pay nothing as it is quite easy to get rid of. If the problem is very severe and a component is damaged, you might have to pay more. There is no proper margin of how much you would have to pay as literally anything could be causing your AC to stink.

Frequnetly Asked Questions:

So, here are some of the frequently asked questions Why Does My AC Stink When I First Turn On My Car? Why Does It Stink When I Turn On AC etc?-

Why Does My AC Stink When I First Turn On My Car?

The reason why there is a distinct smell in your air conditioner when you turn it on is the growth of mould in your air vents. Smells of mildew in your car are caused by the growth of bacteria. As the car becomes mould, fungi, and micro-organisms can start to grow.

Why Does It Stink When I Turn On AC?

Dust, and moisture on the AC filter encourage mildew growth, which can cause a musty odor when the air conditioner runs. This is a reason why the air conditioner smells in winter. To help prevent this odour, replace the filter in the spring.

Why Does My Car Smell Like Rotten Eggs When I Turn On The AC?

A rotten egg smell in your car indicates a malfunctioning part of the fuel system. If the catalytic converter, or fuel pressure sensors are worn out or damaged, a sulfur gas can leak out.

Can A Dirty Air Filter Make Your Car Smell?

If some unusual odor coming from the vents in your vehicle, it can be a sign that needs to be replaced. A very contaminated filter will lead to a dirty, dusty .

How Do You Get The Musty Smell Out Of An Air Conditioner?

You must Fill a spray bottle approximately ¼ full of bleach and then Spray directly into the area where the cool air blows out of the air conditioner. Be sure to get plenty of the solution into the blower fan.


A stinking car AC is very irritating and unpleasant. Almost everybody’s mood would be crushed if their car’s AC stinks. Even though, at first sight, it might seem like a very small issue but it can have a very serious reason. So, I’d suggest you to go to a repair shop and get it fixed. If your car just has the mold issue, you are lucky as you wouldn’t have to go through any hassle. I hope this article helped you stop thinking “why my car AC stinks”?