Gas Cap Not Sealing

The gas cap also known as the fuel filler cap is a simple but important component that is found on the vast majority of road going cars and trucks.

Gas cap not sealing. Today s fuel systems require a complete seal on the tank without it there can be issues. On newer cars the emission control has an engine light which turns on when there is a leakage. Generally gas caps can be used as a closure for the fuel tank. One of the tests is that they verify the gas cap is performing sealing properly.

If the gas cap gasket is pinched dirty cracked or broken it can cause the gas cap to not seal properly and most likely will not click there are a few other parts but they don t impact the caps ability to secure onto the gas tank. What may surprise you is that many new vehicles are being designed without gas caps at all. I can t find anything on the e check website for how they handle when a manufacturer makes a car without a gas cap. If your gas cap is not properly attached you may see a check engine light or a loose cap warning light on the dash.

A modern gas cap serves several functions. Sometimes even new fuel caps have problems like this ac delco gt291 that locks too early. It is a good idea to inspect the seal that is between the gas cap and the filler tube for any tears or cracking that could cause a vapor leak. The gas cap has air vents to allow the air to enter into the tank to maintain pressure.

Then tighten the gas cap with your hand until you hear the cap click in place. These codes typically will be in the p0400 series and could indicate something more serious than a loose gas cap such as a broken seal or even a leak in the gas tank which is a much more serous problem. You can either tighten the cap and wait for the system to reset itself when it determines the problem is fixed or you can use an obd ii code scanner to manually reset the system. Their purpose is simple.

Many cars will also generate a warning signal if the on board computer detects any fuel vapor escaping from the gas tank. The most common cause of a lit check engine light is not a bad sensor it is a loose gas cap. Steve from cars simplified takes a look at this fuel cap on a 2005. March 23 2017 4 23pm.

To prevent dirt debris and dust from entering the gas tank as well as providing a reliable seal. Anyone with info please let me know.