Reasons For Your Car Exhaust Smells Like Ammonia

If your car exhaust smells like ammonia, you are not alone. Many users experience the same phenomenon. Though many try to ignore it, it is not advisable.

There should be something wrong with your vehicle. You will not want it to develop and spend more money on repair later, right?

The article below will explain the possible reasons for car exhaust smells. Besides, if you have some technical knowledge, the tips for repair below will help you avoid the repair cost.

What Is The Regular Exhaust Fume In Cars?

car exhaust smells like ammonia
Exhaust Fume In Cars

Typically, exhaust smells have a musty and smoky odor. It’s difficult to define but rather straightforward to detect by a nose

If your car’s exhaust has a gasoline-like smell, it’s usually because of abnormally rich air.

A typical odor is more pleasing to the nose than that of sulfur or gasoline from a faulty emission system. Should the exhaust smell like a typical emission, you should not worry.

Besides, modern cars are equipped with catalytic converters and fuel injection systems. They can make the exhaust fumes smell less strong.

Depending on the location you smell it, there might be a problem. When you can smell the exhaust smell inside cars, there might be a leak.

Because exhaust contains carbon monoxide, it is a major problem that must be treated promptly.

How A Car Exhaust System Works 

The exhaust system is a mechanism that eliminates toxic fumes from the vehicle. The emissions are discharged by the tailpipe when the fuel is burnt off.

Pollutants such as hydrocarbons, nitrogen dioxide, carbon monoxide, and others are eliminated from the engine.

It will transform from dangerous fumes to a less harmful pollutant. The engine is the starting point for the process. It generates pressure and heat, resulting in the formation of gases.

After that, they are pushed into the engine exhaust manifold with the air.

The gas and air combination is burnt off at the catalytic converter. This procedure eliminates hazardous contaminants. The leftover gases are then driven to the muffler, where they are cooled down.

Now they are ready to be released through a tailpipe.

Why Car Exhaust Smells Like Ammonia?

exhaust smells like ammonia
Exhaust Smells Like Ammonia

The most common causes of the ammonia-smelling exhaust are blocked fuel injection, a defective catalytic converter, or a fuel system leakage.

These components can help convert toxic substances into less damaging gases.

A Leak In The Exhaust System 

An exhaust system leak is one of the typical reasons car exhaust smells like ammonia. For example, pollutants will be released when there is a manifold hole.

Now you can smell the fuel. This leaking fuel smells similar to ammonia because it includes hydrogen sulfide.

Sulfide, a substance present in gas naturally, is a toxic substance with a ruined egg smell. It is extremely harmful to inhale into the human body.

Thus, don’t stay in your car anymore when you scent it. You should call a professional immediately.

A Faulty Catalytic Converter 

Once the catalytic converter malfunctions, it cannot transform the fuel into non-toxic compounds. As a result, the exhaust may contain an ammonia smell.

This phenomenon is because sulfur dioxide and other contaminants occur during the process. Besides, hydrogen sulfide, which is not burnt in this stage, also causes the smell.

When you suspect the catalytic converter is defective, you must change it with a new one. Also, you can try to clean the catalytic converter with a cleaner, which can be bought at a repair shop.

It will also help increase car engine efficiency.

Problems With The Fuel Injection System

A fuel injection malfunction can make the emissions the smell of ammonia. It might result from a defective injector when the fuel injector sends excessive gas into the engine.

However, not all of it burns.

Also, you can discover that the injector system is blocked and needs cleaning. Besides, a blocked choke is another reason for this bad gas smell when you own a carburetor in the vehicle.

Once you suspect this is the case, bring your vehicle to an expert for a diagnostic examination.

Problems With Paint Thinner

The ammonia odor can seep from the paint thinner if you have just finished painting your automobile.

It is due to the presence of hydrocarbons of paint thinner, which is one primary pollutant present in automobile exhaust.

There isn’t much that can be done to remove the smell of paint thinner from the vehicle. To prevent that, you may have no way but to wait till the smells have faded.

You may also use an air freshener to minimize the odor.

How To Fix This Issues

why does my exhaust smell like ammonia
How To Fix When Exhaust Smells Like Ammonia

In case car exhaust fumes smell like ammonia, you can do a few things to solve the problem. The first step is to get the catalytic converter inspected. When it stops operating correctly, it must be changed.

  • Solution 1: If something clogs the emission system, users can try cleaning it or bringing it to a repair shop. When you reside in a region where oil drilling is possible, you should utilize a more environmentally-friendly fuel, including biodiesel.
  • Solution 2: After cleaning your car, get an air freshener made for vehicles. These treatments can be used in combination with vacuuming, although they are most commonly used on upholstery, mats, and carpets.
  • Solution 3: Travel for a minimum of 30 minutes with all car windows open to enable the car to circulate. Contaminants may leak fumes from the car paint. Opening windows will eliminate them in the car atmosphere and unleash trapped odors from headliners, carpets, and upholstery.
  • Solution 4: Apply the paint thinner with an aerosol fragrance. Also, it would help if you used a perfume like pine or apple to cover the smell of it.
  • Solution 5: You may also use duct tape or caulk to plug any holes in the vehicle. A plywood piece can be used to hide a leak in the floorboard. You may also attempt to increase airflow in your automobile by adding vents or buying an air filter.

If these solutions do not stop the smell, you may consider taking the car to a repair shop. It could be a faulty component that causes the smell.

Thus, a thorough inspection will ensure your life and the lifespan of the vehicle.

How Do You Get The Smell Of Paint Thinner Out Of Your Car? 

There are various methods for removing the smell of paint thinner:

  • Step 1: Use an aerosol smell. To cover the odor of paint thinner, use a perfume like pine or apple.
  • Step 2: Vacuum the vehicle and then spray it with an air freshener. However, avoid spraying it around vents because they could react unfavorably.
  • Step 3: Open all the car windows and drive for more than 30 minutes to let the air out. It will disperse any substances in the air and expel any trapped odors.
  • Step 4: To eliminate this issue entirely, consider a more environmentally friendly fuel such as biodiesel.
  • Step 5: You may also mix water and detergent in a spray container to remove stains or smell from upholstery and carpets. When there is a significant stain or strong smell, wash it with soap before spraying.
  • Step 6: Should you notice a paint-thinner odor on your skin or clothes after being exposed to emissions, wash them with baking soda for about 30 minutes.
  • Step 7: Sometimes, the smell can stick to your body. Apply some little baby oil over your hands to remove the paint-thinner odor. When you have no olive oil on hand, baby oil is an excellent substitute.

How To Tell If Your Car Is Polluting?

There are various methods for determining whether your vehicle is damaging the environment.

First, if you notice black fumes rising from the exhaust, your automobile harms the environment.

The automobile contaminates the air when you scent something unusual, like an ammonia smell from exhaust. Car fumes may smell harsher than normal.

It pollutes the air when you can hear a loud sound as you ignite the engine. In case you suspect the vehicle is damaging the environment, bring it to a repair shop for a diagnostic examination.

A technician will tell you what’s wrong and how to correct it.

Frequently Asked Questions

Why Does Your Vehicle Exhaust Smell So Strong? 

There are many possible explanations for why your automobile exhaust smells worse than usual. A malfunctioning catalytic converter is the most prevalent cause.

When the converter fails to function correctly, the vapors may have an ammonia smell in cars.

Another scenario is that something is preventing the emission system. It might lead the gases to build up and become stink.

Furthermore, the exhaust system may be clogged. If this is the case, the car smells like ammonia or sulfur.

What Does Burning Transmission Fluid Smell Like? 

People use the transmission fluid to preserve and cool down the transmission’s gears. When fluid begins to leak, it will get into touch with hot engine components.

This contact can make the fluid heat up and emit a burning odor.

If you notice that the vehicle is burning the fluid, it is advisable to pull over quickly and get it hauled to a repair shop. Driving a car with burning fluid can trigger severe engine damage.

How Can I Stop Exhaust Fumes?

There are several techniques users can try to keep exhaust fumes out of their vehicles. The first thing is to ensure that the car is in proper functioning order and that the emission system is correctly placed.

You may also use duct tape and caulk to patch any holes and leaks in your emission system. You can use plywood to hide a crack in the floorboard.

Besides, it is recommended that you increase airflow by inserting vents and an air filter.

You may try to limit the amount of pollution your automobile emits by choosing a more ecologically friendly fuel. Finally, you can attempt the steps above to eliminate the paint thinner.

Will Catalytic Converters Decrease Smell?

A correctly operating catalytic converter converts hydrogen sulfide in the fuel to sulfur dioxide. This substance has no smell.

Thus, if the converter malfunctions, the exhaust pipe will emit a rotten egg-like odor. The odor is caused by unburned gasoline left.

You will also see darker emission smoke from the tailpipe. The catalytic converter is a key component of the car’s emission system. If it is blocked, the emission flow will be restricted.

Besides, if it is broken, the exhaust system may emit dangerous gas. Cracked and clogged converters can reduce engine efficiency, acceleration, fuel efficiency, and bad smell.


The above are the causes why your car exhaust smells like ammonia. The primary factors of ammonia-smelling automotive emissions are blocked fuel injection, a defective catalytic converter, or leakage in the fuel tank.

Because they all turn dangerous pollutants into less damaging emissions, if damaged, they will emit bad smells

Once the catalytic converter fails or breaks, the gases from the vehicle may create an ammonia odor.

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