Blog - Bad Gas Tank Cap Signs
May 13, 2021
You remove your gas cap every time you fuel up. But somehow, this very significant component is still often overlooked. A failing gas cap could impact motor performance, fuel efficiency, and fuel flow if not replaced properly. Learn how to tell if your gas cap is bad and when it's time for a replacement.
What Does a Gas Tank Cap Do
Your gas tank cap seals your fuel tank and prevents water, dirt, debris, and other hazards from contaminating your gasoline supply. Since the cap is used so often, it can become worn and damaged over time.
Your gas cap is also part of your vehicle's evaporative emissions system (EVAP). When fuel evaporates in your gas tank, your EVAP system collects and recirculates those fumes to keep harmful emissions from being released into the atmosphere. However, a bad gas tank cap throws a wrench in this process and could lead to fuel and emission leaks along with other symptoms.
How to Tell if Your Gas Cap is Faulty
The cap does not tighten properly.
One of the most apparent bad gas cap symptoms is having difficulty tightening or securing it properly to your gas tank. You may notice that the cap doesn't click when you turn it into place, or it might pop back open after you've attached it. If the gas cap doesn't tighten or seat properly, it may be due to stripped rings or general wear and tear.
Your check engine light comes on.
Staring at a newly lit check engine light can be scary. Fortunately, the issue may be as simple as a bad gas tank cap. If you scan and receive an EVAP error code or a bad gas cap code, this could mean your vehicle has an EVAP leak or a loose gas cap. Once a bad or failing fuel cap sets off your check engine light, it can prevent your car from passing an emissions test. It's best to replace your gas cap as soon as possible.
You smell fuel while driving.
A loose, damaged, or misplaced gas cap can cause fuel vapors from the gas tank to leak, resulting in the distinct odor of gas coming from your vehicle. The escaping vapor not only makes driving uncomfortable, but it can also pose a severe health risk. Additionally, gasoline is highly combustible and can ignite when triggered by a spark or fire source.
Common Questions About Bad Gas Tank Caps
Can a bad gas cap cause stalling?
A stalling vehicle is more likely to be caused by a bad fuel pump or problems with a spark plug, the ignition, or the airflow. Additionally, transmission issues and electrical failures may cause your vehicle to stall. So, will a bad gas cap cause a misfire? Not likely. But if you do feel your INFINITI stalling, we recommend bringing your vehicle to an authorized INFINITI service center for a full diagnostic.
Can a bad gas cap cause bad fuel mileage? \
Decreased gas mileage can occur for several reasons, including a loose or failing gas tank cap. If your cap is missing, damaged, or improperly screwed on, the fuel in your tank can evaporate at a rapid rate. This might lead to poor fuel efficiency, released gas emissions that can harm the environment, and more frequent trips to the gas station.
How to Test if a Gas Cap is Bad
Making sure your gas tank cap is functioning properly is a pretty simple task. Use these guidelines to see if your INFINITI's gas cap is in working order or needs to be replaced.
- Inspect the cap carefully for physical damage.
- Ensure that your gas tank cap clicks and doesn't become loose once you screw it into your fuel tank.
- Pay attention to your fuel efficiency. If you notice a sudden decrease in gas mileage with no change to your driving habits, check your gas cap to ensure that it is present and connected correctly.
- Check your car's codes. If your check engine light has come on recently and you receive a (P0455 or P0457) error code, a loose or faulty gas tank cap may be the problem.
There are many different types of fuel caps out there, so it's crucial to select the right replacement. If you need a new gas tank cap, shop genuine INFINITI Parts online to ensure the right fit for your vehicle.
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