Bleach In A Gas Tank: What Happens? (Will Engine Survive?!)

If you’re a person who loves your car, you will not likely put bleach in your gas tank. However, it is not unusual if someone would. So now, we will find out what the outcome would be if there is bleach in your gas tank.

So what will happen if you put bleach in your gas tank? Will your engine survive? Bleach can cause corrosion and rust to your car parts and can damage the engine.

Some people would find it ridiculous and foolish to put bleach in a gas tank. If you want to keep your car, then you must not do this. But there are people with their reasons for putting bleach in the gas tank of a car. 

Today, we will learn all about the effects of putting bleach in a gas tank. If you also wish to know the answer, keep reading to learn more about it.

Bleach In A Gas Tank

What Happens When You Put Bleach In A Gas Tank?

Many people are so curious about what would happen if someone put bleach in a gas tank. Many people believe that putting bleach in a gas tank can ruin the car and ruin the car’s engine. On the other hand, many people think that putting bleach in a car gas tank would do no damage. 

So now, let us clear that up. Let us talk about the short-term effects and the long-term effects of putting bleach in a gas tank.

Short Term Effects

If you pour bleach into a gas tank, you will then experience the short-term effects. The first thing that you’ll notice is that your car’s engine will have difficulty staying running. And if your car will run, then it will run very poorly. 

The effects will vary. How much bleach was added to the gas tank and how much gasoline is left in the gas tank will alter the result with a slight difference. 

If the mixture is more diluted, then it will be slightly better than it is not. But you must remember that the amount of bleach does not matter because even with just a tiny amount of bleach, it can ruin a vehicle. However, it will need a lot of bleach to stall an engine and disrupt the car’s performance and the engine. 

And even if your car can still run after putting bleach in its gas tank, you must not take any chances. There are issues inside your car that must be fixed and repaired as soon as you can. 

When you know that there is bleach in your car’s gas tank, you need to immediately fix the issue because if you do not, the long-term effects of having bleach in your gas tank can do severe damage. And it will cause you even more money and time fixing your vehicle.

Long Term Effects

The next thing you have to know is the long-term effects of putting bleach in a gas tank. This is more dangerous and even more expensive to repair. Bleach is composed mainly of water and chlorine. 

Water can cause corrosion. And bleach is also a corrosive oxidizer. So with that, bleach can cause a lot of rust in your gaskets and seals. 

These are the long-term effects. For example, if bleach is to be put inside a gas tank, your gas tank can already be filled with rust the next day. This is how severe bleach can do. 

If you give it a little more time, like a day or more than just one day, the rust will be able to travel from the tank and into the other components of your car. The fuel contaminated with bleach can also ruin the other car’s other components, especially if you run the engine. 

The fuel can touch the fuel lines and even the cylinder heads. The mixture can ruin these parts. The long-term effect will then have you replacing all the components rusted by the fuel mixed with bleach.  

Will Bleach In The Gas Tank Explode?

It is not very likely that your gas tank will explode. It is possible that your gas tank will explode because of putting bleach in it, but it can be doubtful. This is because the effects will solely focus on the corrosion of the vehicle’s components. 

However, even if the effects will be more on the corrosion, running your vehicle with an engine and components rusted and corroded can be a huge problem.

Does Bleach Ruin A Car Engine?

Yes, bleach can ruin a car engine. However, bleach is made up of ninety percent water and chlorine. So in terms of quantity, the water is much more plentiful compared to the chlorine. 

Chlorine is known to be a caustic and corrosive oxidizer. So if chlorine is directly mixed with fuel, the chlorine will oxidize the fuel and go to the engine. 

If you can still run your vehicle even with the bleach, the first short time will still be okay. But the longer the bleach will stay in the gas tank, it will then rust and eat up all the metal and the rubber parts of the vehicle. 

As a result, there will be toxic sediments inside the vent valve and in the combustion chamber. So bleach can ruin your car engine, and it can have dangerous effects. If you also keep the bleach inside your gas tank and into the engine parts and fuel system, the bleach will cause serious harm.

bleach in gas tank

How Much Bleach Does It Take To Destroy A Car Gas Tank?

There is no telling how much bleach can destroy a car gas tank. Maybe a few drops might not make any difference, and maybe it can indeed make a difference. 

If you put a little bit more than just a few drops, then you might feel a more powerful effect. But for you to stay safe, you have to stick with the notion that any amount can do the damage.

How To Destroy An Engine With Bleach?

You can try it in two ways. First, you can directly put enough bleach into the gas tank and then drive the car for a long time. Second, you can also pour an entire gallon or container into the gas tank. 

If you are done with it, it can already destroy your car engine in just about five to ten minutes. If you also want to wreck the engine, pour everything until the gas tank top is filled with bleach. Run the engine.

How Long Does It Take For Bleach To Destroy An Engine?

Pour enough bleach into the car’s gas tank. Then, just fill it with bleach and run the engine. In just about five to ten minutes, the effect will slowly start. 

Your vehicle will not start soon and will have trouble running. If the car is running, then it will run very poorly. So if you put a large amount of bleach into the gas tank, it can ruin the car’s engine in just a short period.

Can Bleach Be Detected In A Gas Tank?

If you pour bleach inside the gas tank, it will look like just water in the gas tank. If you pour all bleach into the gas tank, then it might be noticed. You have to put a small amount to settle in the bottom and not be noticed.

What To Do If You Think You Have Bleach In Your Gas Tank?

If you think that you have bleach in your gas tank, you must know what to do. Running the engine can be very dangerous for you and your vehicle. So the first thing you have to do is not to start your car. 

Even if you are still unsure if it is bleach in there, it is essential not to run the engine. First, your goal is not to let the engine leave your gas tank by running an engine. Second, you can drop the tank and drain the fuel and bleach that is in there. 

If you want to be safe, it would be wise to replace your fuel filter. You must also remember not to use water in flushing your gas tank. As mentioned, water can cause corrosion.


In summary, bleach is known to ruin and destroy a car’s engine. A bleach consists of water and fuel. With this, water can cause corrosion. 

So if bleach is put in the gas tank of a car, it will cause severe damages. There’ll be short-term effects and long-term effects. The bottom line is a lot of corrosion.



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