How are Fuel Tank Filler Cap issues diagnosed?
Diagnosing a fuel cap would happen during scheduled maintenance for many makes and models of vehicles, or any time there is a detected EVAP leak or lean fuel to air ratio. In both cases, they will be visually inspected for degradation, cleanliness, and presence. Afterwards, if it looks to be in good operating condition, a pressure test with a fuel cap pressure tester will determine if it has failed.
How are Fuel Tank Filler Caps replaced?
Fuel tank filler caps go bad quite often, and many times are replaced due to regular maintenance. Even if the fuel tank filler cap is not replaced, the o-ring which seals the cap to the fuel tank filler neck may be replaced instead. Anticipating more than 100,000 miles from one fuel tank filler cap is not likely realistic. Even if the fuel tank filler cap is not leaking enough to cause an OBD trouble code to be stored in the PCM, the cap will still require replacement if it tests poorly during scheduled maintenance. In order to keep the fuel cap and seal working longer, ensuring the cap and filler neck are clean when refueling.
RepairPal Recommendations for Fuel Tank Filler Cap issues
Using aftermarket fuel tank filler caps is ok in most instances, however some vehicles will need to be replaced with a new cap from the dealership. We recommend doing due diligence to identify of a specific fuel tank filler cap is applicable to your make and model, as a poor match between the ca and filler neck will lead to a fuel cap that works properly, but cannot seal the fuel system.
What to look out for when dealing with Fuel Tank Filler Cap issues
Vented fuel caps are available, but will cause any modern vehicle to function incorrectly. sing a filler cap meant for an older vehicle will likely result in improper fitment, and will result in the symptoms noted. These caps are mainly for carbureted engines and marine applications.
Can I replace the Fuel Tank Filler Cap myself?
Replacing a fuel cap is as easy as fueling your vehicle, and much faster. Be advised that testing a fuel cap requires a fuel cap pressure tester, otherwise there is no accurate way to determine if it is functioning properly. If you do not have a fuel tank filler cap test kit, it is likely less expensive to have it tested and replaced, though replacement is the easiest repair that can be done to any vehicle.