Dangers of a Gas Tank Leak

Fuel prices tend to go up instead of down. Fortunately, you can mitigate the impact on your wallet by driving a vehicle with good fuel economy.

However, a fuel leak can undermine your efforts to regulate your fuel bill. It can also put you and your passengers at risk on the road and even in the garage. The longer you don’t notice or ignore this issue, the more it will cost you over time. Here’s how to identify the symptoms of a fuel leak in your car, SUV, or truck.

What Is a Fuel Leak?

It’s an issue where the fuel tank’s contents seep through a damaged or worn-out component or connector. Any vehicle powered by an internal combustion engine can develop a gas tank leak.

Symptoms of a Fuel Tank Leak

In most vehicles, the fuel tank stores most of the gasoline, with the reserve tank only holding a small amount. If the gas tank leaks its contents, the engine might run on fumes earlier than you expect.

Fortunately, a fuel tank leak will have several warning signs. Keep an eye out for these common symptoms of a leaking gas tank:

Fuel Gauge Goes Down Inexplicably

Start your investigation with the fuel gauge. This instrument provides you with an accurate indication of how much fuel remains in the gas tank.

Large gas tank leaks will cause a significant drop in the value displayed by the fuel gauge. This will typically be more of a problem when a fuel line is breached, leaking, or disconnected and the fuel is leaking out under pressure. A leak in or near the top of the fuel tank won’t leak much fuel but will cause a fuel odor.

Conversely, small leaks can elude your notice unless you park your vehicle for a while. If you suspect a leak, record the fuel level during parking and compare it with a new reading taken half a day later.

It’s rare, but sometimes the fuel pump itself or its mounting plate will leak for one reason or another.

Large gas tank leaks will cause a significant drop in the value displayed by the fuel gauge. This will typically be more of a problem when a fuel line is breached, leaking, or disconnected and the fuel is leaking out under pressure. A leak in or near the top of the fuel tank won’t leak much fuel but will cause a fuel odor.

–Richard McCuistian, ASE Certified Master Automobile Technician

Fuel Smell While Driving, Parked, or Idling

If you constantly smell fuel vapor while inside your vehicle, the gas tank has likely sprung a leak. Gasoline possesses a distinct scent. Depending on the blend, it can smell somewhat sweet or very sulfurous.

Occasionally, you might catch a whiff of fuel while driving. It happens because the engine releases a small amount of unburned fuel vapor, well below the permitted emission levels. The smell should dissipate shortly as air movement carries fuel vapor away from you.

If the smell of fuel doesn’t dissipate, the fuel tank might have developed a leak. You’re most likely to notice the lingering odor when you approach your parked vehicle, driving down the road, or idling while stopped by a red light.

Fuel and Moisture Spots Beneath Your Vehicle

Do you regularly check the ground beneath your vehicle before taking it out for a drive? You can catch a leak early by noticing spots of fuel or moisture below the gas tank.

Gasoline evaporates when exposed to air and heat. That makes small leaks harder to detect since the fuel that manages to seep out will often disappear before you can notice them.

However, large gas tank leaks can drip enough fuel to mark small spots on the ground, especially if you leave your vehicle parked for long periods. Severe leaks can even result in a puddle of fuel.

Consult your owner’s manual for the fuel tank’s exact position. Then check the ground beneath your vehicle. Blacktop or concrete pavement will make it easy to see the dark spots of accumulated fuel droplets.

If grass or other plants cover the parking spot’s ground, look for discolored or dead foliage. Gasoline is toxic to plants, and a fuel tank leak will act like herbicide.

Why Is a Gas Tank Leak Dangerous?

You should always exert care when handling anything related to fuel. Don’t underestimate the risk posed by even the smallest of fuel tank leaks.

Here’s why you should repair a gas tank leak immediately:

Fire Risk

Gasoline burns quite efficiently. Its flammability plays a vital role in the engine’s internal combustion process, which generates power for your vehicle.

However, gasoline can catch fire outside the engine’s combustion chamber. That’s when the fuel becomes a safety liability.

The fuel tank minimizes the risk of gasoline going up in flames by separating the flammable fluid from potential igniters. However, a leak will release fuel into the open, where it only takes a single ember or spark to set it aflame. The ensuing blaze can spread to the fuel tank, potentially leading to a fire.

Health Risk

Fuel leaks aren’t merely fire hazards that can damage property and injure people. They’re also health hazards.

Gasoline contains various chemical compounds that have toxic effects on your health. The most dangerous is carbon monoxide, a deadly gas lacking detectable color or odor. 

Inhaling carbon monoxide can make you feel like you have a cold or flu. You might get a headache or feel nauseous.

Air out your vehicle immediately if you experience symptoms of breathing in carbon monoxide.

Common Causes of a Fuel Leak in a Car

Many fuel tank leaks begin when something hits the tank with enough force to puncture its sturdy material.

Fuel tanks also accumulate wear and tear over years of use. Metal tanks might corrode or develop rust that undermines their entire structure. Meanwhile, plastic gas tanks might deform from exposure to chemicals or extreme heat.

Fixing a Gas Tank Leak

The full extent of a fuel tank repair job will depend on factors like the leak’s cause and severity. Small holes are repairable with epoxy putty, and the patches will last a while. You can even perform the repairs yourself.

However, older or corroded gas tanks are usually far too gone for restoration. In this case, you’ll have to replace the whole fuel tank.

Get a Replacement Gas Tank For Your Vehicle

Consider leaving your car or truck in the garage if the gas tank needs replacement, or at least until you replace this faulty part. Even if your vehicle can still run, it’s unsafe and wastes costly fuel. Thankfully, CarParts.com makes it easy to find a replacement gas tank that’s perfect for your vehicle.

At CarParts.com, you don’t have to guess whether or not a gas tank fits your vehicle. We give you what you need to know about fitment to make it easier to order auto parts online. You can search our catalog of high-grade parts and accessories by year, make, and model through our website’s integrated vehicle selector. Ordering is also a simple and easy process that you can complete with only several clicks or taps. If you live in the continental US and order before noon ET, you can expect your new gas tank to arrive within several business days.

Don’t wait until fuel starts leaking from the gas tank before you start looking for a replacement. Check out our wide selection of competitively priced gas tanks now at CarParts.com.