Your car is a bit more fragile than you might think. Electrical gremlins or a faulty cooling system can stop your car with minimal warning. Moreover, many issues can compromise your vehicle’s fuel system, choking your car of its vital lifeblood. One such issue is water in a car’s gas tank, an imbalance that could harm your car from the tank to the engine. 

Water in your gas tank, or gasoline with water content, can damage your car’s fuel system and stop it in its tracks

Water in the gas tank. It’s a very real concern. Your first reaction might be to shrug it off. After all, it’s just water, right? What harm can it do? It turns out that a little bit of water goes a long way to damage your ride.

How does it get into your tank?

Start with the obvious. A driver might accidentally introduce water to their tank. That, or a malicious person might pour water into a gas tank, not unlike vandals using sugar to clog fuel injectors. Beyond that, condensation may introduce small amounts of water to your tank.

Then there are gas stations. In some cases, poor gas station maintenance can introduce water into fuel mixtures. In other cases, proprietors may sell contaminated gasoline as they would typical fuel. Think it doesn’t happen? A Georgia gas station was recently busted for selling gasoline containing 20% water. That content can cause damage to a fuel system. 

What harm does it do?

For starters, water can impact the combustibility of the fuel in your car. Less flammable material, less “bang” in the combustion process. Further into the impact of water on your fuel, water is corrosive to metal and other materials in your car. Introducing water can corrode parts of your fuel system, like your tank and lines.

Worse yet, fuel with a water content can damage your vehicle’s fuel injectors, the parts that spray fuel into the mixture vital for combustion. As a result, water can cause pricey engine damage.  

How do you know if you have water in your gas tank?

Pay attention to your car. Is it running as it normally does? Or is it idling roughly, stalling, or misfiring? If it’s the latter, there may be water where fuel should be in the combustion process. You may also notice white smoke à la a cracked head gasket. If you notice these issues, take your vehicle to a service center before you cause more damage. 

So, what do you do now?

Ok, so you suspect that there’s water in your fuel. It’s a huge bummer, but now isn’t the time to be morose. Take your vehicle in for service. If you want to remedy your vehicle yourself, start by verifying the presence of water.

Using a siphon and the proper technique, extract some fuel into a clear container. Water will be visible at the bottom of the container due to immiscibility. Once you confirm the presence of water, consider draining the tank, filling it with fresh fuel, and replacing the fuel filter. Finally, consider a water-absorbing fuel additive like ISO-HEET. They’re easy to use and may help extract some of the water from your fuel system.