Internal combustion engines run on a mixture consisting of air and fuel. Water is not in this recipe, but unfortunately, its presence in the fuel system is almost inevitable. We deal with what exactly threatens the ingress of moisture and how to remove water from the gas tank of the car.
Why water in the engine is dangerous
In most cases, excess water in the engine is associated with hydrostroke – a situation where it enters the running engine through the air intakes. This can only happen through the fault of the driver. Usually the cause of hydrostroke is sloppy driving through fords or deep puddles, when water floods the hood and enters the air intake. The more water there is in the engine and the higher the engine speed at the time of hydrostroke, the more fatal the consequences for the engine.
Moisture in the fuel system cannot cause a hydrostroke. The amount of water from the gas tank necessary for such a serious breakdown will simply not enter the running engine: it will stall earlier. If there is not much moisture in the fuel, it will be atomized together with gasoline and evaporate instantly when it enters the cylinders – it will not harm the engine at the moment. However, this does not mean that you can tolerate the presence of water in the fuel system.
For one thing, water causes corrosion in the fuel system. For components like a high-pressure fuel pump or injectors, rust is critically dangerous: they will quickly fail.
Secondly, water interferes with the stable operation of the engine and does not allow it to develop full power. Thirdly, at minus temperatures water freezes, which may result in blocking of the fuel pump, fuel filter and pipelines, and this will lead to difficulties with starting the engine or make it impossible at all – the car will have to be heated to melt the ice.
How water gets into the gas tank
Even if you fill up at a trusted gas station and with exceptionally high quality fuel, water in the gas tank of your car will still be there, although in a small amount. The reason for this is condensate, which is formed in the process of fuel storage and during the operation of the car. During the production of gasoline or diesel fuel, there is no water in them – it appears on the way from the factory to the tank. Temperature variations during the day and night lead to condensation of moisture from the air on the inside of the tanks in which the fuel is stored. This process is common to oil depots, gas station tanks, and the fuel tank of a car.
Water can also get into the fuel system due to refueling with low-quality fuel. The reason may be violation of the storage procedure, which requires each new batch of fuel to stand before it is sold, so that moisture and other impurities settle at the bottom of the container. A deliberate violation cannot be ruled out, when gas stations sell fuel bypassing the cash register and then add water to the tanks to compensate for the volume. Finally, some amount of water may get into the tank at the moment of refueling, if it is raining or snowing.
Once in the fuel tank together with the fuel, the water does not dissolve in it. And gradually due to the difference in density a stable “sandwich” is formed – water is kept at the bottom, and gasoline or diesel is above it. And the layers almost do not mix, even if you drive on serious off-road with constant oscillations of the car up and down and from side to side. That is why the fuel pump is installed at a certain height above the bottom of the tank – so that the risk of water and dirt getting into the fuel system is minimized.
Due to the fact that water is covered by a layer of fuel, even in the hottest weather it will not evaporate on its own. That means that to get rid of water in the fuel system, you will have to use either mechanical or chemical methods.
How to get rid of water in the gas tank
So, there are two ways to get rid of water in gasoline. The mechanical one involves physically removing the water. Some tanks have drain plugs: you can simply unscrew it and drain the rest of the fuel along with the accumulated water and sediment. A more reliable option to remove water from the gas tank is to dismantle the tank, wash and clean it. Specialized services often use units that do the same without removing the gas tank. They suck the dirty fuel, pump it through the built-in cleaning system and feed it back into the tank – after a certain time, this circulation washes out sediment and removes moisture. The mechanical method is good because it allows not only to remove water, but also to clean the tank from dirt and deposits that inevitably appear during the operation of the car.
And how to remove water from the gas tank without removing it? It is worth paying attention to chemical additives. In stores, they are called differently: for example, moisture remover from the gas tank or fuel dehumidifier for gasoline engines. Such products are produced by various brands, their composition may differ, but the principle of operation is the same. To get rid of water, chemists use alcohol, which binds moisture and thereby allows you to mix two liquids of different densities (gasoline and water). Once in the fuel, the water simply enters the combustion chamber in small amounts and there vaporizes without harming the engine.
In addition to its main task – to displace moisture – compositions have various additives that provide, for example, anti-corrosion protection or increase the octane number. But such bonuses have a very short-term effect, so you should not count on them. Another disadvantage of chemical means is that they are powerless against sludge, which accumulates over time and eventually clogs fuel filters.
And you should not consider fuel system dehumidifiers to be all-powerful. In one application, chemical means can remove only a few milliliters of water. If you, for example, accidentally took the wrong canister and poured water instead of gasoline into the tank, there is only one way out – to remove the tank and flush it. And the engine in such situations is better not to start.
In search of advice on how to get rid of water in the tank, you can come across folk recipes. But we do not recommend creating your own displacer of moisture from the gas tank or pouring pure alcohol into the tank. First, you can overdo it and create such a cocktail that will not burn in the engine. Secondly, alcohol provokes corrosion, so you can use your own hands to ensure expensive repair of the car. And even more so, you should not pour other alcohol-containing liquids like glass washer into the tank.
Is it necessary to engage in preventive maintenance to prevent the accumulation of water in the gasoline tank? Manufacturers do not provide such a procedure, so the car does fine without it. The whole point is that you run the risk of making things worse, because under the influence of alcoholic preparations, deposits in the system can detach or dissolve in the fuel. And no one knows where their journey will end. It is better to just try to refuel at the proven gas stations, where they monitor the quality of fuel. And also – do it more often, so that the tank is as close to full as possible. There will be less air in it, and therefore less opportunity for condensation.
For diesel the problem of water is even more acute, so fuel filters of such units have special sumps and water sensors. As a rule, its presence is indicated by an indicator on the dashboard or Check Engine lamp. So it is enough just not to ignore the signals and in time to drain the formed sediment from the filter – many diesel cars have such a possibility.
Totals
- Water in the fuel system “in the moment” is not able to cause serious damage to the car, but over time can provoke malfunctions.
- Water in the fuel tank is always present, and in small quantities it is normal.
- To remove water from the fuel system, you can use mechanical cleaning of the gas tank.
- To remove water, you can also use special moisture-removing compounds that are added to the fuel tank.
- Do not use homemade compounds, alcohol or alcohol-containing liquids to remove water from the fuel system.