“GASCAP” Warning Came On [SOLVED]

Vented gas caps work to vent small amounts of air into the fuel tank line. It comes with a one-way release valve that activates when it senses pressure.

Once it reaches a specific PSI, it opens a little to relieve that pressure.

If the valve’s mechanism isn’t opening as expected, too much pressure can build up inside the tank. Although this issue isn’t necessarily dangerous, it can have an adverse impact on your fuel economy.

When the issue involves a leak, you could be losing over $100 in gasoline each year to simple evaporation.

That’s why the GASCAP warning should be taken seriously when seen. This guide will help you resolve that issue.

“GASCAP” Warning Came On [SOLVED]

The GASCAP warning informs drivers that a leak is present somewhere in the fueling chain of activities. It could be in the tank, fill neck, or gas cap, preventing a vacuum from developing within the system. The fuel fill neck gasket is often responsible if the cap is on tight since air can come through that area.

Should your gas cap fail, the leaks could cause you to lose up to 2% of the fuel in your tank with each fill-up.

Although that doesn’t seem like much, if you filled an 18-gallon tank once per week, you’d be paying for an extra tank of gas each year that you weren’t using.

Installing a locking gas cap solves this problem. You can find generic and OEM options available, so you’ll need to verify that your make and model works with the product found.

If your vehicle runs on diesel, you will need a gas cap that works with that fuel only.

The Stant 10508 Locking Fuel Cap is a great choice that delivers OEM quality construction. It replaces that leaking product that could cause the GASCAP warning to come on, saving some drivers up to two gallons of fuel per month.

You’ll also deter fuel thefts with the locking mechanism. A simple key that says “GAS” ensures that you don’t confuse it with other keys.

If you have a vehicle fleet to manage, they’re keyed the same to ensure that you can access any of them.

What makes the Stant Locking Fuel Cap stand out above the rest of the competition is its focus on these three features.

• Lost Motion. This feature allows the gas cap to have some freedom to turn while it keeps its seal, helping to prevent tank leakage during an impact event or an accident.
• Breakaway Groove. With this option, the cap stays sealed to prevent fuel from leaking during an impact. Even if some of it peels or cracks away after a crash, the fuel won’t come out right away.
• Torque Override. Users hear an audible click when the O-ring that seals the cap receives proper compression.

This unique design even prevents fuel vapors from exiting the system under normal operations. That means you receive an alternative airflow path into the tank if obstructions exist in the vapor management systems.

You’ll even normalize the air pressure within the system during a natural vacuum situation by upgrading to the Stant locking fuel cap.

Symptoms of a Failing Gas Cap

Although the GASCAP warning light coming on is a clear indication that something is wrong with the system, there can be times when the HUD doesn’t provide this information.

That’s why it is essential to know the symptoms of a failing gas cap. When you encounter the following problems with your vehicle, it might be time to purchase a replacement cap to install.

1. The gas cap doesn’t tighten correctly when it always has before. It might not click into place, spin on its threads, or fall out after you’ve put it in place.
2. You can smell fuel while operating the vehicle. It might happen while driving or while the car idles and sends vapors through the neck and cap.
3. If your vehicle doesn’t come with a GASCAP warning light or it doesn’t work, the check engine light might come on instead.

The best way to solve this problem is to install a new gas cap as soon as possible.

If you are miles away from the nearest service station or parts store and lose your gas cap, you can restore some functionality by stopping the filler with a rag. That will prevent fumes from escaping your tank until you can arrive at the next step.

Should you have a fuel leak that is causing the GASCAP warning light and you lose the cap, don’t use a rag. It’ll soak through with gasoline, and that could create a safety hazard if you were to be in an accident.

If you can drive with the GASCAP light on, you can continue operations without the caps secured. You won’t harm your engine by making that choice because a flapper valve stops the fuel from flowing out of the tank.

How to Install a Locking Gas Cap

If you continue to get the GASCAP warning after tightening everything in your system, it might be time to upgrade to a locking gas cap.

Your gas cap can fail for several reasons, ranging from seal degradation to impact damage. Since you’re cranking on them each time you refuel, the threads can get damaged or have the ratcheting mechanism fail.

Some states even test the area for evaporations when emissions standards must get met to certify vehicles for the road.

Once you have your preferred gas cap available to install, you’ll want to follow these additional steps to correct the HUD warning you see.

Step 1: Purchase the Gas Cap

Whether you choose the Stant 10508 Locking Fuel Cap or an alternative option that works with your vehicle, you’ll need to have the replacement available before starting this job. Some makes and models might require you to purchase a new product from the dealership.

It’s also beneficial to look at your dealership for options if your vehicle is under warranty. You might get a low-cost replacement, or the service department might decide to do the replacement work for free. You’ll never know if you don’t ask!

Since fuel efficiency is variable based on the quality and seal your gas cap provides, you must use one made for your vehicle to have a successful experience.

Step 2: Secure the Leash

Most gas caps come with a plastic ring that keeps the product from getting lost. You’ll need to attach this leash to the peg that’s either on the panel that opens or is next to the fuel neck opening.

Step 3: Press the Cap in Place

Once you’ve finished the second step, you can press the new gas cap flush to the fuel filler neck thread. Start rotating it in a clockwise motion (turn it toward the left in a circular motion) until you feel or hear a click. That indicates you’ve secured the unit, and it is now sealed.

At this point, you should see the GASCAP warning disappear when your vehicle is operating.

Please remember to avoid forcing the fuel cap into place on your vehicle. The product should screw into place easily without experiencing any resistance. If you encounter a problem, the size might be incorrect.

Step 4: Place the Key into the Cap

When you purchase a locking gas cap, the mechanism is now ready to be secured. Insert the key as instructed by the product’s manufacturer, rotating it in the correct direction to engage the mechanism.

It’s usually clockwise (to the left), but there is a small chance it could go in the other direction.

Step 5: Test the Gas Cap

It helps to test the gas cap to ensure it is locked before operating the vehicle. Most designs swivel, which means they won’t engage the threads when the cap is open.

If you decide that a non-locking gas cap is your best option, the installation steps are the same from steps one to three.

Since you won’t need to lock it in place, you can skip step four. Please be careful when testing the product because it’s much easier to over-torque this design. You only want to hear one or two clicks.

When more assistance is required to replace your gas cap, please contact a professional mechanic. Some businesses will travel to your home to complete the work for a fair and competitive rate.

How Long Does It Take for the GASCAP Warning to Turn Off?

The GASCAP warning light often turns off immediately once the repair occurs. It can take several minutes of driving if a loose gas cap is responsible for the problem. Should the light stay on, tighten the gas cap again or look at the rest of the system to see if another leak exists.

Solving the GASCAP warning light issue is relatively straightforward. The trick is to find a compatible product to replace one that could be malfunctioning.

If you cross-thread the cap after fueling, you can often solve the issue by screwing it on correctly after stopping.

Once you’ve followed these steps, you should have the problem solved. If the warning persists, check with a trusted mechanic to receive a professional diagnosis.