Lacquer thinner in a gas tank: what REALLY happens?! (explained) (2023)

Some claims state that lacquer thinner helps the engine clean the catalytic converter. You may have read about it on a random social media post or watched a short video on YouTube. So you may be wondering if it's really true when you put it in a gas tank. So you may ask:

If you put lacquer thinner in a gas tank, what really happens?You can do significant damage to your entire fuel system if you put lacquer thinner in a gas tank. Most modern gasoline systems have rubber and plastic parts. Lacquer thinner is very corrosive and can damage your engine. Therefore, it is better not to continue with it and instead have your engine professionally cleaned.

Lacquer thinners have different components and vary from brand to brand. For example, you can find some brands with less corrosive materials, while others may contain corrosive substances, such as acetone. These corrosive components can potentially damage your engine as they can melt the rubber and plastic parts. For this reason, mixing these thinners into your fuel can be a bad idea.

In this article, you'll see our in-depth look at paint thinner and how it can damage your gas tank if you put some in it. This will give you insight into the possible risks that it entails and how to deal with it if someone puts lacquer thinner in your petrol tank.

Without further ado, let's get into it!

Table of contents

(Video) PO420 Myth Busted?? PART -1 Lacquer Thinner in your Gas tank? Will It work??

Lacquer thinner in a gas tank: what REALLY happens?! (explained) (1)

What happens if you put lacquer thinner in a gas tank?

Suppose you put lacquer thinner in a gas tank. In this case, you run the risk of seriously damaging your engine through rust, corrosion and any deterioration of the inside of the tank.

One thing to keep in mind regarding lacquer thinner is that it contains caustic ingredients like acetone. As a result, most elements in your fuel system can be damaged.

For example, the wiring in the tank, the fuel pump and the fuel filter can be damaged. You can also melt the glue that holds all the pieces together.

Basically, even critical parts like the fuel pressure regulator, oxygen sensors, and even the fuel injector itself can get damaged.

If your car's temperature continues to rise, the lacquer thinner can burn exhaust valves and possibly the core of the inverter.

Basically, it has the potential to do a lot of damage. The following are some of the immediate and long-term consequences of pouring lacquer thinner into a gas tank.

Short term effects

Depending on how much lacquer thinner you put in a gas tank, the short-term effects can vary. A small amount of lacquer thinner, for example in a fuel tank, is not likely to cause problems.

(Video) Will a Gas Engine Run on Paint Thinner? Let's find out!

However, you may notice a smoky exhaust and a sluggish engine. So even if the small amount of lacquer thinner isn't dangerous, it's still not a good idea.

Long term effects

Suppose you have some lacquer thinner left in your gas tank. In this situation, you run the risk of contaminating your fuel, resulting in poor performance and eventually wear and tear on your engine system.

Lacquer thinner is not a good choice for the engine. As a result, your car will suffer long and short term damage.

Can lacquer thinner in a gas tank damage an engine?

Yes, lacquer thinner in a gas tank can damage your engine. Lacquer thinners include acetone and other acidic compounds.

Your fuel system, especially in newer vehicles, is full of fragile rubber fittings and plastic parts. If you use a corrosive substance, such as lacquer thinner, you risk damaging it.

In other words, it can damage such components, causing rubber fittings and pipes to deteriorate and plastic components to melt.

How much lacquer thinner in a gas tank will ruin it?

An engine can be ruined with a single can of lacquer thinner. Think about what happens if you keep running your engine after two fills with lacquer thinner contaminated fuel. In that case, your engine may be temporarily shut down.

A simple mixture of lacquer thinner and gasoline can foul the entire engine system. As a result, it will hurt the overall performance of your car and cause significant problems and problems.

(Video) Does Lacquer Thinner cleans carbon on pistons/intake valve cleaning/decarbonize engine with water

Lacquer thinner is not compatible with spark ignition engines as it is a lighter diesel mix. As a result, a lacquer thinner tank will most certainly not start. As a result, your car will not drive properly after two fills with lacquer thinner contaminated fuel.

Can you tell if someone put lacquer thinner in your gas tank?

Yes, you can tell if someone has tampered with you and put lacquer thinner in your gas tank. If this happens, the lacquer thinner will react with the gasoline. As a result, the lacquer thinner can cause poor combustion and smoky exhaust fumes when the engine is started, damage it, and the gasoline begins to burn.

Your vehicle creates a lot of smoke due to poor combustion. You need to turn off your car and check if it is running and producing a lot of smoke. Another danger is that if the lacquer thinner is not burned, it can block the engine.

Lacquer thinner can clog your engine because it leaves residue. As a result, there is a good chance that your car will come to a standstill, resulting in damage over time.

If you suspect that someone has put lacquer thinner in your gas tank, shut them down and have them investigated as soon as possible to avoid problems.

Lacquer thinner in a gas tank: what REALLY happens?! (explained) (2)

How to get the lacquer thinner out of a gas tank?

If there is lacquer thinner in your gas tank, get it out immediately. However, it can be a complex process.

The engine must be switched off and the petrol tank must be emptied. You will most likely also need to replace the fuel filter.

(Video) PO420 Myth Busted?? PART -2 Lacquer Thinner DID IT WORK?? A real test!

If your gas tank has a cap or access from the top of the trunk, this is excellent. In that case you can look inside. In certain cars it is generally located under the back seat.

The lacquer thinner in the tank can react with the fuel, and in most cases it does. As a result, you need to drain the old fuel and replace it with new.


In short, lacquer thinners have no place in a petrol tank. Lacquer thinner in a gas tank can cause significant damage to an entire fuel system and the damage can even spread to the engine.

Since modern fuel systems contain rubber and plastic parts, the thinner can melt or dissolve such parts. So it is better not to put one and secure your car to prevent someone from doing this.

Finally, as a rule of thumb, don't put any kind of lacquer thinner or thinner in your gas tank. This way you can prevent problems with the engine and fuel system.


  • Tampon in a gas tank
  • Water in a gas tank
  • Rust in a gas tank
  • Too much heat in fuel tank


Image Credits - Canva


Lacquer thinner in a gas tank: what REALLY happens?! (explained)? ›

Similarly, being a flammable liquid, lacquer thinner is a severe fire hazard in your gas tank. The rising temperatures from your running engine may ignite the solution and burn your exhaust valves. Therefore, putting lacquer thinner in your gas tank results in a smoky exhaust and a slow engine.

What happens if you put lacquer thinner in your gas tank? ›

Similarly, being a flammable liquid, lacquer thinner is a severe fire hazard in your gas tank. The rising temperatures from your running engine may ignite the solution and burn your exhaust valves. Therefore, putting lacquer thinner in your gas tank results in a smoky exhaust and a slow engine.

What does lacquer thinner do to a car? ›

Lacquer thinner is so powerful that it will even soften cured, dried lacquers and other oil-based coatings. Lacquer thinner can damage plastic and rubber and it can even strip car paint. Lacquer thinner acts quickly and aggressively to dissolve lacquers.

What can I put in gas tank to clean catalytic converter? ›

Top Catalytic Converter Cleaners
  • CataClean Fuel Cleaner 16.7oz. ...
  • Rislone Cat Complete Fuel, Exhaust and Emissions System Cleaner 16.9oz. ...
  • CRC Guaranteed To Pass Fuel System Cleaner 12oz. ...
  • Chevron Techron Fuel System Cleaner 12oz. ...
  • Gumout Regane Complete Fuel System Cleaner 12oz. ...
  • STP Ultra 5-IN-1 Fuel System Cleaner 12oz.

What is the best catalytic converter cleaner? ›

Best Catalytic Converter Cleaners
  • CRC “Guaranteed to Pass” Emissions System Formula.
  • Cataclean Engine and Catalytic Converter Cleaner.
  • Sea Foam Motor Treatment.
Dec 10, 2022

What does acetone in gas tank do? ›

But adding too much acetone to gasoline will speed up the flame burning too much, and adding too little will not influence, or speed up a little, the fuel burning.

How do you unclog a catalytic converter cheaply? ›

What can you do? Drive the car at high speeds for a few miles. Try to get to 2500-3000 RPMs. This way, the exhaust system heat will burn off the catalytic converter deposits and unclog the converter.

What dissolves catalytic converter? ›

The process developed by the U.S. Bureau of Mines takes advantage of the unique properties of cyanide to selectively dissolve platinum-group metals from automobile catalytic converters and recover a metal concentrate. Cyanide is a traditional industrial chemical used in the recovery of gold and silver.

How long does lacquer thinner take to clean catalytic converter? ›

To clean your catalytic converter, start by adding pure lacquer thinner to a half-full gas tank. Next, set out for a day trip. You'll want to drive about 150 miles at high speeds. If you prefer, you can run the engine at about 2500 RPMs for about 30 minutes to allow the cleaner to run through the converter.

How much lacquer thinner to put in gas tank? ›

If there is something wrong with your car's catalytic converter, your car will likely give you a check engine light. Upon plugging in an OBD reader, the code it throws will most likely be P0420. To clean the converter, pour about a quart of pure lacquer thinner into the car's gas tank.

Will acetone clean a catalytic converter? ›

With 175,000 miles, I don't begrudge this wonderful car a repair once in a while, though so far it hasn't needed too many. lacquer thinner is mostly acetone, and it will NOT clean your converter because it will never reach your converter. It will burn completely in the engine.

What is the difference between thinner and lacquer thinner? ›

Lacquer thinner is not the same as paint thinner. It is too caustic for oil paints, whereas paint thinner is comprised of mineral spirits that are typically used to thin oil-based paints. Lacquer thinner is hotter than paint thinner, and if often a superior cleaner than mineral spirits.

How much lacquer thinner do I put in my gas tank to clean my catalytic converter? ›

Some mechanics who still recommend using lacquer thinner to clean a catalytic convert recommend adding one quart of lacquer thinner to seven gallons of gas, followed by running the car for a long distance at higher speeds to pass the lacquer thinner vapors through the exhaust system.

How to fix a clogged catalytic converter without replacing it? ›

Fuel additives, like Cataclean, are one of the first and easiest methods to try for fixing a catalytic converter issue. Just add the product to your fuel tank and then drive your car for 15 minutes.

Will seafoam spray clean catalytic converter? ›

Sea Foam Spray is safe for catalytic converters and O2 sensors [SOLVED]

How long does it take catalytic converter cleaner to work? ›

Dump all the bottle's contents into your fuel tank. This is the same place where you would put gas. Step 2: Drive your vehicle for at least 15 minutes to allow the Cataclean to get into your vehicle's parts. Step 3: If you have error codes on your on-board computer (OBDII), clear them after you've driven the vehicle.

Can bleach clean catalytic converter? ›

To avoid damaging your catalytic converter during cleaning, avoid the following: Soaking the component in grout-eating gel, bleach, or similar corrosive chemicals that can damage the catalyst. Pouring paint lacquer or thinner in your gas tank.

Will catalytic converter cleaner fix a clogged catalytic converter? ›

You can unclog your car's catalytic converter with a catalytic converter cleaner or by removing the part to pressure wash and degrease it before reinstalling it.

What does isopropyl alcohol do in a gas tank? ›

For a typical 40-gallon fuel tank, one half to one pint of isopropanol will disperse the water and get your engine running satisfactorily. The water that's now dispersed in the fuel is said to actually improve engine performance.

What does isopropyl alcohol do in gasoline? ›

Mixing alcohol with gasoline produces gasohol. Advantages of fuel blends are that alcohol tends to increase the octane rating and reduce carbon monoxide (CO) and other tailpipe emissions from the engine. The octane number of a fuel indicates its resistance to knock (abnormal combustion in the cylinder).

What happens when you mix diesel and acetone? ›

A tiny bit of acetone in diesel fuel can stop the black smoke when the rack is all the way at full throttle. You will notice that the exhaust soot will be greatly reduced. Acetone can reduce hydrocarbon emissions up to 60-percent.

How do you know if your catalytic converter is completely clogged? ›

If you're noticing slow powertrain performance, reduced acceleration, a smell of rotten eggs or sulfur from the exhaust, dark exhaust smoke, or extreme heat from under the vehicle, these are symptoms of a clogged Catalytic Converter, and it should be replaced quickly.

What are the 3 most leading failures of a catalytic converter? ›

Most catalytic converter failures fall under one of three categories: Overheated, melted or broken converters.

How do thieves remove catalytic converters so fast? ›

How Do Thieves Take Them? Unfortunately, stealing a catalytic converter is very easy to do. Thieves usually slide underneath a car with a battery-powered reciprocating saw and cut it right out of the exhaust line. It takes about 2 to 3 minutes and makes as much noise as any other power tool.

Will antifreeze destroy a catalytic converter? ›

Not only will this cause major engine damage, but the antifreeze can enter the exhaust system and block the air passages with a heavy carbon-like soot. These carbon deposits will prevent the catalytic converter from doing its job of reducing harmful gases in the exhaust.

How much platinum is in a Cadillac converter? ›

A standard catalytic converter contains about 3 – 7 grams (0.106 – 0.247 ounces) of platinum.

What does lacquer thinner remove? ›

As the name suggests, a lacquer thinner is meant to thin and clean lacquer, which is a type of wood finish. A high-quality lacquer thinner is made up of different solvents that can dissolve lacquer and resins. Therefore, it is a very effective cleaning agent for thinning lacquer-based paints and varnishes.

How long do you leave lacquer thinner on? ›

Apply Paint Thinner

Check the manufacturer's directions and allow the paint thinner to sit for the required amount of time. It typically takes about 20 minutes for the paint to soften.

How long does it take lacquer thinner to evaporate? ›

10ml in a large 55mm open cup at 20o Celsius and 20o Celsius ambient temperature will begin to evaporate after 2 hours. Any airflow on the surface will accelerate the evaporation process.

How long does lacquer off gas for? ›

Most coatings get their final cure after 30-40 days, but in enclosed areas (like inside the boxes) what is off-gassing could certainly hang around for a while longer. They should wait the 30 days and use Simple Green to clean the boxes. If there are lights nearby, have the bulbs changed out too.

What can I coat the inside of my gas tank with? ›

Gold Standard Tank Sealer will stop rust and form a tough, fuel impervious coating while sealing small pinholes and weld seams. Your fuel will never touch the inside walls of your tank again.

How flammable is lacquer thinner? ›

Extremely flammable. Keep away from heat, sparks, flame and all other sources of ignition. Vapors may cause flash fire or ignite explosively. Do not smoke.

Can you clean a catalytic converter with dish soap? ›

Dish soap and water should be added to a large bucket. Soak the catalytic converter, which is now dismantled, in the bucket overnight. Make sure that the converter's honeycomb is free of debris. If so, replace the catalytic converter and reassemble the exhaust system.

Will oven cleaner clean a catalytic converter? ›

Run water and oven cleaner through the cat. Spray the oven cleaner in the cat and let it sit for a few minutes. Then run water through the car while blowing air in at the same time. Rinse, then install and drive the car until the cat is hot.

Is lacquer thinner just acetone? ›

Although they are often used interchangeably, there are significant differences between the two. Acetone is a colorless, flammable liquid that is primarily used as a solvent, while lacquer thinner is a mixture of various solvents used to dissolve and dilute lacquer-based paints and coatings.

What are the benefits of lacquer thinner? ›

Lacquer thinner can easily soften and thin away paints that are difficult to remove as they have turned solid and flaky on smooth surfaces. Some can be used eliminate leftover residue from cements and plastics. These thinners can also be used on clothing made of natural fibres to remove varnish stains and paint spots.

What is another name for lacquer thinner? ›

Lacquer thinner, also known as cellulose thinner, is usually a mixture of solvents able to dissolve a number of different resins or plastics used in modern lacquer.

Can I pour lacquer thinner in my gas tank? ›

Absolutely not. Lacquer thinner formulas vary from brand to brand and may contain substances such as acetone which are harmful to your fuel system, especially rubber and plastic parts. Unless you can positively verify the chemicals in the lacquer thinner you're using, I wouldn't put it in the fuel system.

Why should you spray paint your catalytic converter? ›

By adding bright paint, you can create a visible deterrent to alert thieves to move on. This paint also signals law enforcement and recyclers to look deeper for serial numbers or identification marks. By clearly marking your catalytic converter you will be deterring the theft from happening in the first place.

Why wont my car run without a catalytic converter? ›

Driving without your car's catalytic converter means you'll expel very high concentrations of carbon monoxide — an extremely harmful emission. Most deaths caused by carbon monoxide poisoning occur while operating a vehicle inside enclosed spaces.

Can a car run without a catalytic converter? ›

Technically, a car can function without a catalytic converter. However, this is not a sustainable long-term option.

Can a clogged catalytic converter damage engine? ›

Usually, a clogged catalytic converter will overheat and can have damaging impacts on your car's engine. Anytime you experience an engine misfire, contact a reliable mechanic right away for catalytic converter repair or replacement services.

What's the best catalytic converter cleaner? ›

Best Catalytic Converter Cleaners
  • CRC “Guaranteed to Pass” Emissions System Formula.
  • Cataclean Engine and Catalytic Converter Cleaner.
  • Sea Foam Motor Treatment.
Dec 10, 2022

Will lacquer thinner clean a carburetor? ›

As a solvent for cleaning the gunk/ residue in our carbs, this one works.

What clogs up a gas tank? ›

Dirt, sediment, and carbon buildup are all common things that can clog these fuel system parts. Dirt and sediment can also clog your fuel lines and prevent gas flow into the engine.

What will lacquer thinner remove? ›

Lacquer thinner can easily soften and thin away paints that are difficult to remove as they have turned solid and flaky on smooth surfaces. Some can be used eliminate leftover residue from cements and plastics. These thinners can also be used on clothing made of natural fibres to remove varnish stains and paint spots.

Can you pour lacquer thinner down the drain? ›

Never Dump Down the Drain

Paint thinner is highly toxic and should never be dumped down the drain, in order to avoid contaminating waterways. Instead, dispose of as Household Hazardous Waste (HHW).

Is gun wash the same as lacquer thinner? ›

Gun Wash is a specially formulated lacquer thinner designed specifically for cleaning spray guns and lacquer painting equipment.

How can you tell if someone put something in your gas tank? ›

1. Know the Signs of a Contaminated Fuel Tank
  • Sputtering engine.
  • Stalling on idle.
  • Failure to start.
  • Whitish exhaust.
Jan 12, 2018

Why should a gas tank never be completely filled? ›

Gas topping damages your car.

Gas in the system can affect your car's performance by causing it to run poorly, and damage the engine, he says. "When we overfill the tank, it sends all of the excessive fuel to the evaporation/charcoal canister and kills the life of that canister," Carruso says.

Will JB Weld seal a gas tank? ›

JB Weld TankWeld kit is the perfect repair kit for your broken fuel tank. The bond is petroleum resistant. It is great for stopping leaks with no welding required!

What is the best way to seal a hole in a gas tank? ›

  1. Step 1 - Jack up the Vehicle. ...
  2. Step 2 - Find the Leak or Hole in the Gas Tank. ...
  3. Step 3 - Sand the Leaky Area of the Tank. ...
  4. Step 4 - Clean the Surface. ...
  5. Step 5 - Mix the Epoxy. ...
  6. Step 6 - Shape and Apply the Epoxy. ...
  7. Step 7 - Insert the Epoxy in the Hole. ...
  8. Step 8 - Fill the Tank with Gas.
Jan 27, 2012

Can you use Flex seal on gas tanks? ›

A: No. We do not recommend using Flex Tape on a gas or oil tank.

What are the hazards of lacquer thinner? ›

Hazard Statement(s)

Highly flammable liquid and vapor. May be fatal if swallowed and enters airways. Fatal if inhaled. Harmful if swallowed or in contact with skin.

What temperature does lacquer thinner ignite? ›

This paint thinner SDS identifies it as a Category 3 flammable material in terms of the OSHA standard. This means it has a flash point in the range 73.4 to 140 F (23 to 60 C).


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