What Happens If You Get Water in Your Fuel
By: Leon Rhodes
If you get water in your fuel the result is poor engine performance and, ultimately, engine damage. Water doesn't burn so the combustion process is compromised but what happens is potentially more serious than that.
The severity of issues created by having water in your fuel depend on the amount of water present. This is what happens when water gets into your fuel.
Hard to Start
White Exhaust Smoke
Injector Steam Damage
Clogged Fuel Filter
If a significant amount of water is present in your vehicle's fuel system you will typically find it hard to start the engine, if not impossible. Fuel and water don't mix but both can be pumped to the engine as it sloshes around in the gas tank.
When that happens combustion becomes difficult to achieve and no matter how hard you try the engine simply can't run properly so it stalls and sputters, if it starts at all.
Small amounts of water in your fuel often becomes visible in the form of white smoke coming from the exhaust system. This is caused by steam from the hot exhaust system condensing as it exits the tail-pipe.
Prolonged contact between water and metal creates rust and corrosion which can damage the inside your engine. From the inside of your gas tank to the cylinders of your engine, and everything in between, rust will eventually form wherever water is present.
A small amount of water in your fuel may not be enough to stop the engine from running but it may still cause steam damage. Steam is what happens when water is flash-boiled by hot engine components and the resulting pressure can damage components like hot injectors.
To run properly an engine goes through combustion cycles and when water randomly interrupts those cycles it robs the engine of power it needs to run smoothly. Every shake and shudder has the potential to cause engine wear and fatigue.
Some fuel filters, especially in diesel engines, separate small amounts of water from fuel. As the fuel filter fills with water it becomes less capable of allowing fuel to pass causing a clogging effect.
In winter water can be especially damaging of fuel lines and engine components when it freezes. As water freezes it expands and if there is no room for expansion the resulting ice will break metal components. Not even cast iron will withstand the force generated by water turning into ice if there is no room for expansion.
How does water get in fuel?
The most common way water gets into your fuel is through the process of condensation. Air in your fuel system contains a small amount of water and a temperature difference between the inside and outside of your gas tank causes water particles in the air to condensate into droplets. Keep the tank full to minimize this effect during hot summer months.
How do I get water out of my fuel system?
The easiest way to get water out of your fuel system is to drain the fuel completely, including from the tank. What is sometimes difficult is diagnosing how the water got there is the first place. Make sure the tank has no leaks on its top side or water will return.
Is there an additive to remove water from fuel?
Yes, however, additives work to disperse contaminants so that they may pass through the engine which, depending on the amount of water you have in the system, can cause more damage than it prevents. Follow manufacturer recommendations carefully.