How to clean a fuel tank of rust – Secret revealed

So, you are thinking about restoring that old car or motorcycle? Maybe it’s an antique, and maybe it’s a classic one. Either way, if it has a fuel tank, there is a fair chance of some rust in it. If you plan to restore the vehicle’s finish, the rust in the tank will have to be removed. Here I’ll show you several ways on how to clean a fuel tank of rust.

To clean the fuel tank and get rid of rust, you should get the fuel out of the tank, seperate the tank from the car, clean with water and soap and then apply anti-rust spray inside the tank to prevent future rust. You should allow the fuel tank to get dry before you apply any anti-rust sprayer. 

The most important area of the engine that owners often overlook is the fuel tank. The fuel tank can be a place where rust can start to occur. In the real sense of it, you do not want rust to take place in your car tank; else, it will cause some damages to your car engine.

Rust is probably the most common issue for steel fuel tanks. When fuel goes bad, it tends to form a layer of rust on the inside of the tank. This is usually caused by improper storage or not filling up with fuel soon enough after getting gas. Cleaning them can sometimes be a challenge if you have new, used, or rusted-out fuel tanks.

Some will demand you remove the tank from the car to wash thoroughly for effective cleaning. Also, you can choose to wash so that you do not have to remove the tank. Either way, you end up getting your task done.

So, let’s go through how you can clean your fuel tank if you ever have it filled with rust. Your first step to cleaning your tank is to get quality fuel tank cleaner. There are many you can get out there in your local stores or on amazon. One of them is the WD-40 Specialist Rust Remover Soak.

How to clean a fuel tank of rust

How rust impacts your vehicle?

You need to be aware of the danger of rust in your car tank so that neutralizing rust on cars will not be optional but a matter of urgency for you.

If you think that rust in your car engine doesn’t affect performance, then I’d like to tell you otherwise. The truth is that rust not only deteriorates the physical appearance of your tank, but it can also cause irreparable damage to it and some to your engine if you choose not to do anything to it.

The truth about the whole thing with rust is that it may break free and then travel with the fuel through the injector or fuel lines to your engine. It will then make the engine work abnormally. Rust will surely invade the fuel filter and then hamper the fuel flow.

It will then affect your car performance as it will start to move sluggishly on acceleration. Also, the debris from the rust can damage the engine, so you should never take it as a small issue.

How to clean a fuel tank of rust?

1. You should get fuel out of the tank

The first thing that you need to do when cleaning your tank is to get the fuel out of the tank. If you have the tank filled, you should get the fuel out. You can do that by locating the fuel hose that connects to the tank and then remove to collect the fuel into the can or keg.

2. Separate the tank from the car

Separating the tank from the car might be such a difficult task for you to do. You should allow an expert to do this task for you. However, if you are a DIY lover just like me, you have got nothing to worry about.

So, if you are doing the task yourself, you need some essential tools. First, you need to raise the front section of the car just the way you do whenever you want to change the car tire. Do ensure you use a strong hydraulic lift that will raise the car enough for you to move under.

Get enough lift stand as I will suggest you get four stands. Position the stand under the car, and then you can be sure moving under the car is safe for you. Now, you should reach out to your ratchet and socket to loosen the clamp on the fuel filter tube and vent tube.

Once you have done that, you should disconnect the hoses from the tank, disconnect the fuel lines, filler tubes, vent pipe, and others before you lower the tank on the ground. If you do not know or you are forgetful, you should snap or keep a picture of each stage so you can find it easy to re-install.

3. Clean, patch, or replace the tank

You should then move on to clean the tank once you have removed it from the car. Take it closer to your faucet and allow water to flow through the tank. Once you have done that, you should make use of a fuel tank washer in the tank.

Some chemicals such as nitric acid, acetic acid (white vinegar), phosphoric acid, hydrochloric acid, sulfuric acid, muriatic acid, oxalic acid, and citric acid can do the magic. You just need to pour any of them into the tank carefully with your gloves on.

Shake the tank as easily as you can. You can leave for thirty minutes and then wash off by running water through the tank. You should keep running water until it is clean. Then you can leave the tank to dry off before you install it back in your car.

Also, before you install, you can apply fuel tank flush or chemicals that help prevent further rust accumulation. Prevention is indeed better than cure.

How to clean a fuel tank of rust

How to remove rust from inside a diesel fuel tank?

There are many ways to remove rust from inside a diesel fuel tank. Some are effective, but others are not. Effective are often simple, easy to do, and maybe free or cost little money.

Also, do not remove rust from inside the tank while it is still in the car. Having rust come loose inside a running vehicle could cause damage to the engine or clog hoses and create other safety problems.

The truth is that some petroleum micro-organisms largely cause contamination in diesel fuel tanks. Treating your tank with a biocide agent will surely help extend the lifespan of the tank.

If you want to wash the tank, you should follow the same procedure as said above. Once you have done that with removing the tank, you should pour a few gallons of water and a scrubbing material in the tank.

You can make use of clean gravel and then add liquid soap with petroleum cutting properties such as Ajax, Palmolive, and dawn, and you can swish the mixture in the tank vigorously as possible.

Once you have done that for minutes, you can empty the tank and run clean water through it. After that, you can allow the tank to dry.

Read: Flat tire – what to do?

How to clean a rusty gas tank with muriatic acid?

One of the ways you can clean the rusty gas tank is through the use of muriatic acid. Before applying muriatic acid in the tank, you should have your safety goggle, hand gloves, and nose mask in use.

Place the tank on the floor while you carefully pour the acid into the tank. Once you have poured the acid into the tank, you should carefully move the tank in a circular motion to ensure the acid is evenly distributed inside the tank.

Leave the tank for one hour or more and then lift a part to get rid of the acid in the tank. Run through water and finish up with fuel tank flush, then leave the tank to dry before you re-install in the car.

How do you get rust out of a fuel tank?

There are just two ways you can get rust out of a fuel tank, which I discussed on this page. The first process is through the use of water and some fuel tank cleaner kits. The second is through the use of chemical products, which is quite dangerous and requires more concentration.

However, the two are productive and thus require you to remove the tank from the car before doing anything. To remove the rust, you need to remove the tank, clean it with the right material, leave it to dry, and then re-install it back to the car.

What is the fastest way to clean rust out of a gas tank?

The fastest way for you to get rid of rust in a gas tank is to bypass the process of removing the tank. You just need to lift the tank and ensure you have the stand beneath to keep it secured. Then you can go under to disconnect the fuel tube and all others that link to the engine.

If the tank still has gasoline, you should empty it into the can or key. Then you can pass a hose of water through the gas opening to flush the tank. You can go ahead with adding anything you wish to add, and you should not be under the car while doing this.

Once it is done, you have to leave the car for minutes to dry off and then use an air dryer or blower to ensure no moisture is left in the tank. After that, you can fix back the whole tube and wires you disconnected in the first place.

How do you clean sludge out of a plastic gas tank?

If you’ve got a plastic gas tank, you should use water and soap to do the cleaning. Some chemicals will react with the plastic material and damage the tank.

So, it is best that you only use some scrubbing materials with water and soap to wash. You should shake vigorously once you have them all in the tank, and you will get to see the result.

How do you clean a metal fuel tank?

The best way to clean a metal tank is through the use of chemical substances. I have mentioned above some chemicals you can use to clean your metal tank.

If by any chance, you choose to use water to clean the tank, you need to ensure you blow the tank as any trace of water can lead to rust formation in the tank.

Also, you need to ensure that you use a fuel tank flusher, which will help prevent rust formation after washing the tank.

How do you clean a contaminated fuel tank?

The first step to cleaning a contaminated file tank is to get the fuel out of the tank. You should get a fuel injector and pour it into the tank. The product works so that it prevents the contaminated particles from getting through the fuel into your engine.

It destroys them, and they pass out as gas emissions. Also, you can go through the process of washing thoroughly either with water or chemical.

How do I clean out my gas tank without removing it?

The best way to clean your gas tank without removing it is to raise the car, empty the tank, disconnect all you have to, and then wash.

The only challenge is that you might end up leaving water in the tank. So, you should ensure you make use of an air blower to keep the tank completely dry.

What happens if you put vinegar in a gas tank?

Vinegar is also a good consideration for cleaning a gas tank that is corroded. It works great at ensuring it breaks down the rust properties and prevents the formation of new ones.

How bad is rust in a gas tank?

You don’t just want to leave rust in your tank if you care so much about your car engine. The engine of the car is at risk if you do so. The fuel will run to the engine through the hose or tube, and some rust particles can follow that same part.

Once they finally travel to the engine, it disrupts the engine’s performance, and you get to experience sluggishness with your car. Also, it can damage the car engine.

How to keep the gas tank from rusting after cleaning?

If you are asking, how do I keep my tank from rusting? I will tell you that you should ensure you use a fuel injector or polisher once a month. The product helps in ensuring that no form of rust takes place on the car tank.

Also, you can choose to use a flusher now and then as prevention is better can fixing the tank once the rust formation occurs.


This page is a comprehensive one on how to clean a fuel tank of rust if you are faced with such challenges. We have you covered with all you need to know about rust, the effects on your car, and how to get rid of them in different scenarios.