Automobile manufacturers recommend keeping your gas tank full. Besides fueling your vehicle, sufficient gas in your gas tank is a coolant for the fuel pump motor. But some car owners try to make a bang for their buck by overfilling the gas tanks.
But many wonder if there are negative effects to overfilling your fuel tank and what you can do if you accidentally do it.
The gas pump nozzle automatically shuts off when your gas tank is full. But suppose you continue pumping fuel or the gas pump auto shut-off fails to engage.
In that case, the fuel will overflow onto the ground, into the charcoal canister and damage the Evaporative Emission System. This will lead to increased emissions, reduced engine performance, stalling, and even a check engine light.
This article will explain what happens when you overfill your gas tank and the symptoms of an overfilled fuel tank to be aware of the dangers and avoid them.
What to do if you accidentally overfill a gas tank
The correct way to fill your car’s fuel tank is to stop when the nozzle shuts off. Although the pump nozzle has a sensor that helps to stop the fuel when the gas tank is full, you can still overfill your tank accidentally.
Below are actions you can take when gas overflows when filling the tank:
- You should first turn off the engine and allow the car to sit for a few minutes. This allows the excess gas to drain back down into the tank.
- Then clean up the spillage. If the fuel tank overflows onto the car outside, it creates a fire hazard. The car can catch fire if a spark occurs anywhere near the spillage. Gasoline spills are also harmful to the environment. Take a rag and some soapy water and clean off the excess gas on the outside of your car. After this, wash your hands thoroughly, as gas can irritate your skin.
- If you have some expertise, you can remove the spark plugs and clean them with a wire brush or sandpaper. This helps to remove fuel that may have overspilled onto the spark plugs. In addition, keeping the plugs clean ensures they function properly so your car can run smoothly.
- You can also drive your car fast to burn off the gas. This is safe to do as gasoline evaporates very quickly.
- Finally, take your vehicle to a mechanic to thoroughly assess the damage and make the necessary repairs.
What happens if you overfill your diesel tank?
Although gasoline and diesel are different fuels, any liquid fuel that gets into your EVAP will affect your car’s performance and damage the engine. This is because the EVAP only processes and filters the excess fuel’s vapor, not the liquid itself.
Overfilling your diesel tank may seem harmless, but it can damage several components of your car. Below are some of the negative effects of overfilling your fuel tank.
Floods the engine
The excess fuel will flood the engine and over the cylinders with gas, leading to several issues, such as:
- The spark plugs will corrode, leading to misfiring, sputtering, and engine damage.
- The air filter will become clogged and reduce airflow and increase emissions.
- A gas film will form on the windshield, thus reducing visibility and increasing the chances of an accident.
Ruins the EVAP system
The engine has an EVAP(Evaporative Emission Control System) that traps and burns fuel vapor from the fuel tank instead of venting it out to the atmosphere. Therefore, it helps prevent harmful emissions. But overfilling your diesel tank will force liquid fuel into the EVAP and compromise it, thus requiring a replacement.
Although you can drive with a faulty EVAP system, it can lead to more expensive repairs. In addition, since it will lead to increased emissions, your car will also fail an emissions test.
Leakage
Fuel tanks need some air in them to allow the fuel to expand and evaporate efficiently. If your fuel tank is full, the EVAP system can break or become strained, causing a hazardous leak.
Check Engine Light
Overfilling your fuel tank can trigger the check engine light to illuminate. When your fuel overflows, the fuel system will activate the vapor recovery, and the tank vent will flood with fuel.
The vehicle’s computer will then sense the flooding in the vent system and know there is a problem in the fuel tank. This will clean the valve function and throw a code that triggers the check light engine to come on.
You can drive the vehicle around to see if the light goes off. If it doesn’t, there may be an issue with the fuel tank vapor system. So you will need the help of a mechanic to diagnose the code and repair it. If the check engine light disappears, then you’re good to go.
Premature fuel pump wear
If you overfill your diesel tank too frequently, it can also cause the fuel pump to break down prematurely. Your fuel pump requires your fuel tank to have enough fuel because it acts as a coolant for the fuel pump motor, preventing wear and preserving the functionality of your fuel pump.
Although accidentally putting too much gas in your car once or twice may not damage the car, but its best to completely avoid it. You can remove the gas pump nozzle from your car’s gas tank and replace it on the pump. When you hear a ‘thunk’ noise, it means your gas tank is full.
Removing the nozzle will also stop the transaction; therefore, you will not be charged for gas pumped after your leave.
Signs and symptoms of an overfilled gas tank
Ideally, you will hear a click in the nozzle to indicate the tank is full. The fuel pump will then automatically stop the fuel. But some people never hear the sound, so below are several ways to tell if you have overfilled your gas tank.
- After a refill, the fuel gauge needle points beyond the “F” (for full) symbol.
- The filler neck is bulging, or the cap becomes difficult to remove.
- The smell of gas in your car’s cabin. Fuel vapors will escape into your car, which could be harmful to your health and also a fire hazard.
- A check light engine after a fuel refill.
Conclusion
As you can see, there are several reasons why it’s important not to overfill your fuel tank. First, it is harmful to both the environment and your car. If you frequently overfill your gas tank, you’ll damage the EVAP system and engine, leading to performance issues and more expensive repairs.