How to Fix Water In Gas Tank? Symptoms and Effects

The presence of water in a gas tank can be seen as a major issue that requires immediate fixing because it can seriously damage your car or vehicle by slowly reducing the engine’s efficiency and performance by severely affecting the injectors and the fuel pipeline. In most cases, it results in damaging the engine permanently.

This problem can be caused by weather conditions, which lead to condensation in the fuel tank, or it can also be due to filling up the fuel tank from the pump. Allowing water to stay in a gas tank is a very terrible idea and can lead to severe damage that can incur a very high cost for repairs. Highlighted below are the causes, symptoms, and effects of water in a gas tank and the processes taken on how to fix the water in a gas tank?

How does water get in a gas tank?

The following are the major ways water can drip into a gas tank;

water in gas tank symptoms

Intrusion of water

Rainwater can easily enter the fuel tank if you forget to close the fuel door after refueling your car. If the gas tank has a puncture in it, it will allow water penetration into it.

Low-quality gas

The presence of low-quality gas in a fuel tank is another cause of this problem; it can be due to a damaged water filter from the gas station you normally fill up your gas tank. A damaged filter implies that the fuel pumped into your gas tank has some water content.


It has been researched that an environment with a humid weather condition with a significant temperature change can cause 0.81 Oz (0.0296 liters) of water vapor to be formed in an empty gas tank of about 190 gallons of fuel capacity. The water vapor will condense into water and may even develop to a high volume if the water is not removed from the tank.

The gas produced by the refinery

It is not a common factor, but there is a certain level of possibility. If there is a malfunction in any machine in the refinery whose job is to prevent a mixture of water with the gas, it will lead to poor quality fuel at the gas stations.

Faulty top fuel pump

Some modern cars have their fuel pump installed on top of the fuel tank, seen under the front seats. These cars are more prone to have this issue because if the fuel pump seals are damaged, it can result in a high accumulation of water in the fuel tank, especially when the car passes through deep floods.

Symptoms of water in a gas tank

You have to know the signs that reflect the water content in the fuel tank. Below are some of the symptoms to note when your car has this type of issue but make sure you take it to the mechanic for proper certainty of the cause:

The engine could abruptly halt when driving

Water presence in the fuel tank makes it very difficult to combust the gas to occur. In a situation where there is a little amount of water in the fuel tank, it can stop and stop the engine at various intervals, but in a case where there is a high volume of water, your car won’t start.

A decrease will occur in the mileage of the car

The water inside the fuel tank will contaminate the fuel, reducing the motor power’s efficiency and finally causing a decrease in your car’s mileage. It happens because the engine burns the fuel that comes into it regardless of the water in the fuel.

Trouble in accelerating the car

If you notice there is water in your gas tank, it will lead to poor acceleration or hesitation in the car’s movement. The fuel system is no longer pumping gas into the engine; instead, it pumps the gas tank’s water.

The engine of the car will not be able to kick-off

When there is a high water volume in the fuel tank, it will not allow the engine to kick off. The piston is unable to complete a rotation. After all, the water inside the car’s cylinder is above the piston. This situation prevents the combustion of the fuel from taking place, which hinders the engine from kicking off.

Jolting or sputtering of the car, you accelerate.

A car with water content in the gas tank is bound to experience jolting or sputtering the car when the driver tries to accelerate. Jolting or sputtering occurs when the engine system injectors take in water instead of gas.

what happens if you put water in a gas tank

Effects of water in the gas tank

It can damage the fuel injector

Refusal to remove the water in the gas tank can permanently damage the injector. Accumulation of water in the gas tank can cause corrosion of the injector and the entire fuel system. It will cause the fuel system to fail and prevent the engine from starting, which means you will not drive the car.

Reduction in the efficiency of the accelerator

When driving a car that has high water content in its gas tank, that vehicle may hesitate when pressing down the accelerator, or it may even start jerking. You will be unable to drive smoothly on a highway as a result of this issue. You might also experience sudden fluctuations in the speed of your car while driving. It will make your vehicle very difficult and not safe to drive.

It damages the whole fuel system.

Since gasoline has a lighter weight than water, the fuel will set to settle at the top of the gas tank while the water will settle at the tank’s bottom. Vehicles that pump gas from the bottom of the tank may pump water into the engine, and also, the presence of water at the bottom of the gas tank can lead to rusting and damage to the hoses and pipes that transport the gas.

The ignition system of the car will not be able to function

It will not be possible to start your car at all when you have a high volume of water in your gas tank, or you have left water in it for too long. Most times, it looks as if there is no fuel in the tank because as you try to start the car immediately, it goes off.

Damage to the engine

The pumping of water to the engine system can completely damage your car’s engine because it cannot undergo water combustion. It will damage the various parts of the entire engine and might lead to a permanent shut-down.

How do you fix the water in a gas tank?

It is paramount that when you notice the presence of water in your gas tank, you should immediately remove the water from the gas tank before it causes permanent damage to either the engine or the fuel system. The fuel injector is usually the first part of sustaining any form of damage, and buying such a part is very costly. The longer time you spend removing the water in your gas tank, the more damage it will cause, and the more money you will spend on repairing the damage. To prevent this, adopt the following to fix the issue of water in your gas tank;

how does water get in gas tank

Seek the services of a mechanic.

For instance, if you cannot properly remove the water from the tank, you should consult a mechanic to assist you in taking care of this problem and how to get water out of the gas tank. It is advised that you report the problem to your service center and request a mechanic’s services. In cases where you have high water volume in the gas tank, you will have to drain the fuel and buy new fuel filters completely.

Use fuel additives

Many products contain fuel additives and methanol that can be used to solve effectively remove water from your gas tank. Still, fuel additives will not properly function when there is a lot of water in the fuel tank.

Usage of rubbing alcohol

Applying rubbing alcohol to the gas tank can help to absorb the water present in the tank. When the rubbing alcohol is applied and helps to remove water from the gas tank with alcohol, it gives a mixture that is not considered dangerous or harmful to the engine. Although it is not the best option to completely fix the issue, it is a good alternative, but it is advisable to consult the right professionals for guidance.

Drain and replace the gas.

It is a method that is seen as the best way to get rid of this problem completely. Completing out the contaminated fuel and replacing it with high-quality fuel containing ethanol will effectively resolve this issue. It should be known that fuel containing ethanol, in the long run, causes an accumulation of water in the gas tank, and those types of fuel have low efficiency.

Addition of octane fuel

It is regarded as another method to fix this issue. Pouring a large amount of octane fuel into the gas tank will help to remove the water content. Octane fuel has the needed properties to remove all moisture content and keep the gas tank dry. I strongly recommend that you use BOOSTane Professional OCTANE Booster.

How to Remove Water from Gas Tank YouTube


The engine is the most vital and most expensive car component, so appropriate attention is needed to prevent it from getting damaged. Water presence in a fuel tank can damage the whole engine system, so it should not be left long in the gas tank. Be aware of how water can enter your gas tank and take the necessary measures to prevent it. But immediately, you notice any of the symptoms mentioned that indicate water gas in the tank. Make sure you take the most appropriate measure to fix the water in the gas tank completely.


Hi there, I am R. Hasan Tito, a mechanic, and owner of this website. My friend and I created this website to share our knowledge, expertise, and experience with our fellow mechanics' community and car users. I am a specialist and certified automotive mechanic (Both Heavy Commercial and Private Cars). I worked as a Mechanic and Mechanic Supervisor for over fifteen years at Global Rebound Automotive companies - Toyota, TATA, BMW, Nissan, TVs, and Others. Now, I enjoy my new role of leading a team of automotive experts (in their respective fields) and publish new content on a regular basis on my website and social media.

Leave a Reply

Your email address will not be published. Required fields are marked *

Recent Posts