Why Does My Car Exhaust Smell Like Paint Thinner? (Explained)

Considering the important roles your exhaust is tasked with, you should be very keen when you notice any changes.

A lot of people don’t often pay much attention to their exhausts. This can however slow engine performance, increase fuel consumption as well as affect how the exhaust removes harmful gasses from the engine.

If you have noticed a paint thinner-like smell coming from your engine, you need to have it checked right away. Obviously, you may be curious to know what is causing this smell and that’s what this article is going to address.

We are all familiar with the smell of paint thinner. And having to endure this smell in your car can be irritating, plus, you may be subjecting your car to more harm.

There are several causes of a paint thinner smell coming from the exhaust or other parts. We are going to look at the different causes so that you can narrow them down to the particular issue affecting your vehicle.

why does my car exhaust smell like paint thinner

Can Bad Oxygen Sensors Cause paint Thinner-Like Smell to Come from Exhaust?

If you take your car to the mechanic complaining of a paint thinner smell coming from the exhaust, the first thing they will check are the O2 sensors.

A bad oxygen sensor can lead to the production of a paint-thinner-like smell from the exhaust.

To confirm whether the oxygen sensors are the problem, you should be on the lookout for the following signs. They include; a car running irregular when idle or sounding rough.

If not fixed in due time, the car may start accelerating slowly and stall from time to time.

The oxygen sensors are responsible for controlling the air to fuel ratio in the engine. If they fail, they may cause the car to run rich whereby more fuel than air is being channeled to the engine.

It is important that if you replace the 02 sensors if you notice the above symptoms alongside the paint thinner smell issue. Failing O2 sensors can throw on the check engine light but this isn’t always the case.

Does the Smell Only Come If You Start the Car When It’s Cold?

There are rumors that some companies add fuel additives to gas, especially during winter to help the engine get to operating temperatures faster.

As a result, when you start the car, you get that smell of gas mixed with some chemicals that smell like paint thinner.

If this is the case, then you have got nothing to worry about as long as when it’s warm, your exhaust doesn’t smell like paint thinner.

We can’t be certain that the above is true, and at the same time, we can’t ignore this because several car owners have shared this on various forums.

If you think that you are experiencing the same, try and source gas from another company. And observe if you will still notice the paint thinner smell. If symptoms persist, visit your mechanic for diagnosis.

Can a Fuel Leak Cause Paint Thinner Smell in the Car?

Yes, a fuel leak can cause a paint thinner smell in the car. But it won’t come from the exhaust. The first place you should check is the fuel sender lid. Confirm if it’s closed properly.

Look for leaks under the carpet in your trunk or beneath the rear seat. The leaks can also be somewhere along the fuel system. You should be able to see drops under where your park the car in the morning.

Though fuel leaks may not come from the exhaust, driving in a car with such a problem is risky. Have a mechanic identify the leak and fix it for you.

Plus, not unless the gas you use has additives, the smell shouldn’t be that of paint thinner.

At times, a fuel leak can be caused by a failing pulsation fuel damper that may cause gas to drip on the engine. This can also cause a paint thinner-like smell. It will however be stronger at the front than at the back.

What if the Paint Thinner Smell is Coming from Heater Vents?

In some cases, certain car owners notice a chemical or paint thinner smell coming from the vents whenever they are driving or idling.

Though it may seem straightforward, have you recently carried some paint thinner in your back seat or trunk?

In these modern days, it is normal to be so busy that you carry and forget you have paint thinner in the car. If you are sure that the smell is coming from heater vents, then you should check your coolant level.

Coolant is known to have a chemical or sweet smell when it is heated. And chances are, the coolant could be leaking to the heater core of your vehicle and that’s why you are getting that paint thinner smell.

The only way to diagnose if your coolant is leaking is by performing a physical check.

The most common smell that comes from the AC vents is of decaying flesh. And this usually comes from a dead animal somewhere along the vents.

Different Types of Smells Coming from Exhaust and Their Causes

Car smells are always an indication that there is something wrong. Not unless the smell is caused by spilling something accidentally in the interior, you have got nothing to worry about.

You should however be very concerned when you notice a strange smell coming from the engine or exhaust. Here are the different types of smells that can come from the exhaust and what causes them.

  • Smell of rotten eggs – Often caused by a broken catalytic converter

This is the most common smell that comes from exhausts and car owners are familiar with it. The smell of sulfur or rotten eggs is a sign that your catalytic converter isn’t working correctly.

This can also cause your car not to run at all. So, if you smell rotten eggs coming from the exhaust, have it checked by the mechanic as soon as possible.

  • Smell of mold – Caused by Mold Growth behind the dashboard

If you are familiar with how car AC’s work, then you know that pulls moisture from the air. When this happens, the excess water is removed via a drain.

With time, the drain gets clogged and this creates the perfect environment for mold growth. The mold may come up through the AC vents and it is very dangerous for you to breathe mold.

To prevent this, always have the AC compartment cleaned regularly. This will prevent blockage of the drain discussed above.

  • Sweet smell – Mostly caused by leaking coolant

A leaking coolant creates a sweet smell when it drops onto the engine when it’s running. There are two dangers of driving with a leaking coolant. The engine can overheat easily and also, the leaking fluid can damage the engine.

  • Smell of pungent smoke – Caused by oil leaks

Similar to the above, an oil leak also has its dangers. The engine requires oil to run, if there is no oil in the engine then it may knock.

Secondly, oil leaks can cause fires when they find their way into the exhaust. If you notice a strong pungent smell of smoke, stop the car and contact a mechanic right away.

  • Smell of exhaust fumes – Caused by a leaking exhaust

Exhaust fumes can also leak into the cabin and this increases the level of carbon monoxide buildup. When you notice the smell of exhaust fumes, roll down the windows and stop the vehicle. Immediately ask for help.

As you can see from above, many types of smells can come from the exhaust. All these smells indicate a problem with either the engine or other parts that are needed for the vehicle to run.

Never ignore weird smells coming from the exhaust. And thanks to the above guide, you are not only educated on what causes pain thinner-like smell from the exhaust but other smells and the issues that could be causing them.

Can the Smell of Paint Thinner Make You feel Dizzy?

First things first, you shouldn’t be smelling gasses from your exhaust. You may ask and how am I going to know if there is a weird smell coming from the exhaust?

If there is something wrong with your car, you won’t have to bend down to your exhaust to sense a certain smell. Most of the time, these smells will be strong enough for you to notice them when you are in the car or standing next to it.

One of the uses of the exhaust is to release harmful gasses from the engine. And these can affect your respiratory health if you inhale these gasses in large amounts.

If you have sensed that your exhaust is producing an odor that smells like paint thinner, avoid inhaling it as it may make you feel dizzy.

Surprisingly, some people love the smell of paint thinners, mineral spirits, or turpentine. Even if you belong in this category, do not inhale paint thinners because they are toxic.

The ingredients found in paint thinners are harmful when ingested and inhaled and that is also the case with smells that resemble it.