Lacquer Thinner in a Gas Tank: What REALLY Happens?! (Explained)

Some claims state that lacquer thinner helps the engine in cleaning the catalytic converter. You may have read about it on a random social media post or have watched a short clip on youtube. Thus, it may make you wonder if it’s actually 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 cause significant harm to your entire fuel system if you put lacquer thinner in a gas tank. Most modern gasoline systems have rubber and plastic components. Lacquer thinner is highly corrosive and can harm your engine. As a result, it’s better not to pursue it and instead get your engine professionally cleaned.

Lacquer thinners have different components, and it varies from brand to brand. Thus, you can find some brands with less corrosive materials, while others can contain corrosive ones such as acetone. These corrosive components can potentially harm your engine as they can melt the rubber and plastic parts. For this reason, it can be a bad idea to mix these thinners with your fuel.

In this article, you’ll see our in-depth take on lacquer thinner and how it can damage your gas tank if you put some in it. This way, you can understand the possible risks it involves and how you should deal with it if someone puts lacquer thinner in your gas tank. 

Without further ado, let’s get into it!

Lacquer Thinner in a Gas Tank

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

Suppose you put lacquer thinner in a gas tank. In that case, you risk causing serious harm to your engine due to rust, corrosion, and eventual deterioration of the interior of the tank.

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

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

In brief, even critical components such as the fuel pressure regulator, oxygen sensors, and even the fuel injector itself might be damaged.

If your car’s temperature continues to rise, the lacquer thinner might burn exhaust valves and possibly the converter’s core.

In a nutshell, it has the potential to do a lot of harm. The following are some of the immediate and long-term consequences of pouring lacquer thinner in a gas tank.

Short term effects

Depending on how much lacquer thinner you put in a gas tank, the short-term consequences may vary. A small amount of lacquer thinner, for example, in a fuel tank is unlikely to cause any issues.

However, you could 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 leftover in your gas tank. In this situation, you run the danger of polluting your fuel, which will result in poor performance and eventually wear out your engine system.

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

Can lacquer thinner in a gas tank damage an engine?

Yes, a lacquer thinner in a gas tank may cause harm to 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 components. If you use a corrosive substance, such as lacquer thinner, you risk damaging it.

In other words, it has the potential to damage such components, causing rubber fittings and lines to deteriorate and plastic components to melt.

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

An engine may be ruined with a single can of lacquer thinner. Consider what happens if you continue to run your engine after two fills with lacquer thinner-contaminated fuel. In that case, your engine may be momentarily disabled.

A simple mixture of lacquer thinner and gasoline can cause contamination of the whole engine system. As a result, it will harm the overall performance of your car, as well as cause significant issues and problems.

Lacquer thinner is not compatible with spark-ignition engines since it is a lighter diesel mix. As a result, a lacquer-thinner tank will very certainly fail to start. As a result, after two fills of lacquer thinner-contaminated fuel, your automobile will not run properly.

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

Yes, you can tell if someone messed 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 may cause poor combustion and smokey exhaust when the engine is started, harm and the gasoline begins to burn.

Your vehicle will create a lot of smoke as a result of poor combustion. You should shut down and check your automobile if it is running and creating a lot of smoke. Another danger is that if the lacquer thinner is not burned, it can block the engine.

Lacquer thinner might block your engine since it leaves residues in it. As a result, your car is likely to come to a halt, resulting in damage over time.

If you suspect someone has placed lacquer thinner in your gas tank, turn it off and have it examined as soon as possible to avoid problems.

Lacquer Thinner in Gas Tank

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

If lacquer thinner is in your gas tank, you should take it out immediately. It may, however, be a complex process.

The engine should be turned off, and the gas tank should be emptied. You’ll also most likely need to replace the fuel filter.

If your gas tank has a cap or access from the trunk’s top, this is excellent. You are allowed to look inside if that is the case. In certain automobiles, it’s generally found beneath the rear seat.

The lacquer thinner in the tank may react with the fuel, and it happens in most cases. As a result, you’ll have to drain the old fuel and replace it with new.


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

Further, since modern fuel systems contain rubber and plastic parts, the thinner can melt or dissolve such parts. Thus, it would be better not to put some and to secure your car to avoid someone from doing so.

In the end, take it as a rule of thumb not to put any kind of lacquer thinner nor any thinner in your gas tank. This way, you can avoid engine and fuel system issues from happening.



Image credits – Canva

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My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more