Water in Gas Tank Symptoms: Causes & Solutions


Many car owners do not notice a problem when there is water in the car’s gas tank.

Usually, it is present in small numbers, so hardly anybody notices this phenomenon.

But experience shows that if there is water in the gas tank, the consequences can be unpredictable.

In most cases, it promotes corrosion on metal surfaces.

The presence of excess fluid can cause some components and devices of the power unit to stop working.

So you need to get rid of the water in the gas tank as soon as it occurs before it leads to malfunctioning.

As for diesel engines, the occurrence of moisture in the fuel contributes to improper operation of the injection pump, because it disables the pump element.

To prevent such problems, you need to know where the water in the tank comes from, what are the symptoms of this phenomenon and how to fix it.

Symptoms: During Winter

During winter, the easiest way to determine if water has got into the tank is if the engine cannot start.

This is because the moisture freezes in the pipes, depriving them of their capacity.

The fuel stops moving around the system and the engine cannot run.

In order to solve this, you can put the car in a heated garage and the ice melts itself.

But it is not always possible, so you can force the pipeline to warm up.

To do this, we must switch the fuel supply off, and the starter has to be turned until gasoline flows out of the exhaust pipe.

This will be enough to start the engine.

But do not forget that it is still necessary to get water out of the tank, because the ice barrier in the pipelines will occur every single time the car is cooled down again.

Symptoms: General

Image of gas tank

Car won’t start:

As in the cold, problems with starting the engine can also occur in summer.

Therefore, information on how to get rid of water in the tank will also be useful in warm weather.

In this case, motor problems occur if the fuel pump has taken a lot of water from the tank and the combustible mixture cannot ignite.

There is also a chance that the engine could be hydro-locked if it doesn’t crank.

Water can not be compressed like air, and when the pistons try to compress the air in the cylinder they cant, because water can’t be compressed.

This will cause the engine to lock completely and could even damage the internals of the engine, such as the crankshaft rods.

This isn’t very common, and there’s got to be a lot of water in the chamber to make this happen.

Inflammable fuel:

The second sign that the tank needs to be cleaned from water is the engine friction.

It means that the combustible mixture is inflammable, but since part of the fuel has been replaced by water, a lot of oxygen remains in the exhaust fumes, creating harmful compounds with other substances.

Slow acceleration:

The third sign, which requires the driver to know how to remove condensate from the tank, also comes from the engine.

When water is present in the fuel/air mixture, the vehicle accelerates slowly as the total power of the piston cylinders is reduced due to gasoline shortages.

All these signs of water in the tank should not be ignored, even though power reduction and friction of the power unit are possible for other reasons.

Check engine light:

Although very rarely, the check engine light can appear indicating that there is something serious with the engine.

Usually, if it got to the point where check engine light appeared then there something more then just water in the gas tank.

How To Reset Check Engine Light

Why is there water in the gas tank?

Anyone who understands what will happen if the gas tank is filled with water will react to the formation of moisture in the fuel supply system.

If you already have experience in dealing with this issue, the car owner will take measures to reduce the likelihood of water appearing.

Before we consider what to do if water gets into the gas tank, let’s figure out how to reduce the likelihood of moisture and understand the main reasons for this phenomenon.

Image of gas tank

Human Factor:

Often, the owner of a car does not even ask how to remove water from the car’s gas tank until he begins to add various additives to the fuel that increase its properties, and along with these compounds, water gets into it.

Therefore, by improving some indicators, the car owner worsens other properties of the fuel.

Also, moisture can get in even at the gas station, if its composition was deliberately changed in order to increase the volume.

As a result, the owner of the car is expected to remove moisture from the gas tank.

High humidity:

Another reason many people are interested in how to get water out of the car’s gas tank is that the environment is more humid.

Because of the excess water present in the air, it condenses inside on the walls of the fuel tank and then flows over them without mixing with the fuel.

They are two different substances, and the gasoline is lighter, so it’ll be upstairs and water downstairs.

Gradually its volume will increase, and at some point, the fuel pump will capture it and will go to the combustion chambers.

When water entered this way, the symptoms will be visible as droplets on the lid of the fuel tank.

Incorrect fuel storage:

This applies to those people who store fuel in containers with a lot of air from which condensation occurs.

If storage conditions have been violated, the fuel already has a certain concentration of moisture when it enters the vehicle.

Temperature change

When day and night temperatures are noticeably different.

As night comes, the walls of the gas tank cool down faster than its contents if the car stays outside overnight.

Because of this, when warmer air comes into contact with cold metal, condensation is formed and it is necessary to clean the tank from water.

How to remove water from the gas tank:

Removing water from the tank is not a complicated procedure, but you need to know the sequence of actions.

There are many ways to solve this problem but we’ll consider the most effective ones. 

Demonstration of gas and water. gas is on top, and water is on the bottom.

Without removing the gas tank:

It’s worth mentioning that you won’t be able to drain the tank completely.

However, limiting its volume is a task that can be solved by replacing fuel and constant refuelling.

This is one way to remove water from the tank without removing it, but it is expensive because you need to keep the fuel level at maximum to reduce the air volume in the tank.

Given that the level needs to be monitored regularly, this method is not considered rational, as there are more efficient methods.

Fuel Additives:

The last, most reliable way is to add special alcohol-based additives.

This substance interacts with water to form a substance of approximately the same density as gas.

As a result, moisture does not precipitate or freeze.

Besides, such liquid burns in the combustion chambers.

Thus, the use of additives designed to displace water is considered the most effective way to solve this problem.

Prevention measures

Finally, I will give some simple but useful tips to help prevent the phenomenon of water accumulation in the fuel tank of your car.

There’s nothing complicated about it. Just stick to the following recommendations:

  • Avoid unfamiliar and questionable gas stations
  • Try not to open the lid of the tank without reason
  • Make sure the lid is tight
  • If the weather is humid, always fill the tank as full as possible
  • Change the filter in time
  • In the autumn season, you can add about 200 ml of “alcohol” to your full tank
  • Periodically (preferably in autumn season) remove the tank, clean and dry it.


Leave a Comment