Water in the gas tank? (Common symptoms and how to eliminate them)

Do you think you have water in your gas tank and want to drain it? Water in the gas tank is very common in older cars with rusty tanks and poor tank breathing. However, these problems also occur in newer vehicles.

As you probably already know, unfortunately cars don’t run on water and if you have water in your gas tank, your car certainly won’t appreciate it.

But how do you know if there is only a small amount of water in the gas tank and how do you remove it? In this article we will talk about these issues. Let us begin!

The most common symptom of water in the gas tank is harsh acceleration or a misfire. You may also notice signs like a check engine light on your dashboard or white vapor coming out of the exhaust pipe.

Although these symptoms probably didn’t help you much, they will give you a quick overview. Here is a more detailed list of the most common symptoms of water in gas tanks.

Water in the gas tank Symptoms

1. Sudden acceleration

Probably the most common sign of all gas tank symptoms is harsh acceleration. Because the engine thinks water is fuel, the air-fuel mixture will be very strange in the combustion chamber.

It can often be felt with a very sudden acceleration.

2. Misfires

Because of the issues we talked about earlier regarding what will happen when water enters the combustion chamber, you will likely also notice misfires when water enters the cylinder’s combustion chamber.

Misfires and harsh acceleration can be two fairly similar symptoms, as misfires can cause harsh acceleration, but you may also notice misfires while idling.

3. Hard slow motion

Rough idling is also a common symptom due to a faulty air-fuel mixture and misfiring. The car engine is susceptible to minor errors at idle, and it is at idle that you will notice the most symptoms of water in the gas tank.

4. Check engine light

Modern cars have full-time monitoring of all car sensors If a sensor receives incorrect values, it will send the information to the engine control unit which will store a trouble code in memory and sometimes turn on the engine light if the problem is serious.

If your check engine is on your dashboard, it’s definitely time to look for trouble codes with an OBD2 scanner.

5. Exhaust steam

When you have water in the combustion chamber or exhaust pipe, it evaporates and creates steam. We probably all know what happens if you cook water over 100°C: it will evaporate and turn into steam.

So if you notice a lot more vapor than normal coming out of the tailpipe, it could be due to water in the gas tank.

6. Slow acceleration

All the sensors in the car ensure that the air and fuel mixture is in perfect mixture all the time.

If water flows through the engine, the sensors will get an incorrect reading and cause the engine to run too rich or too lean. This can cause reduced engine power and you may see symptoms such as slow acceleration.

7. Difficult starting condition

The starting time of any automobile engine is very critical. The fuel mixture must be almost perfect, or the spark plugs will not have enough fuel to ignite the fuel, or it will become flooded and will not be able to create ignition at all.

If you have water in the gas tank, it is horrible for starting condition and you may have trouble starting it. If you notice long boot times, check this.

8. The engine does not start at all

There may be so much water in the fuel that the engine does not start at all. It’s also possible that your engine is hydro locked if it won’t even start. Water cannot be compressed like air, and when the pistons try to compress air in the cylinder, they will try to compress water, which is impossible.

This will cause the engine to stop completely and could even damage internal engine components such as the crankshaft connecting rods. This is not very common and there must be a lot of water in the chamber for this to happen.

If you suspect this to be the case, remove a spark plug to ensure that the crankshaft can rotate afterward.

9. Problems appear after the car has been stopped for a while

Fuel floats on water, and water will remain at the bottom of the fuel tank when the vehicle has been stopped for a period of time. When the gasoline pump The pump, fuel and water are mixed. If the vehicle has been stopped for a while, water will be at the bottom of the tank.

Most fuel pumps draw fuel from the bottom of the tank and what will happen if the car has been running for a while? – Yes, the fuel pump will only pump water into the engine.

How to remove water from the fuel tank

So now you know the symptoms and causes, and you’re sure you have water in your gas tank. Now is the time to learn how you can get rid of them.

There are different solutions for this and here are some tips, depending on the amount of water you have in the fuel tank.

1. Drain the tank and replace the fuel filter and fill

The best way to remove water from the gas tank is to empty the tank with a vacuum, replace the fuel filter, and refill it.

You need a vacuum machine to suck all the water out of the tank, so it is best to take this job to a mechanic shop with these machines to do the job for you.

You can also pump it with the built-in fuel pump but remember that the fuel pump is often installed a few millimeters from the bottom of the tank and some water may remain at the bottom.

If you are thinking of getting one of these machines for your workshop, I can recommend this manual storage machine from Amazon:

Remember to replace the fuel filter after doing this.

2. Fill with some methanol or special fuel additives

If you think you have some water in the fuel tank, you can try to remove it with methanol or by using a special fuel additive for this purpose.

Remember, this will not remove much water from the fuel tank and only works if you have a small amount.

To get one of these fuel additives, I can recommend the one on Amazon:

Read the instructions carefully to ensure you do not damage the motor or other parts. To test it with methanol, be very careful and use only small doses of methanol.