A steady, lingering whiff of gasoline in or around your car is more than just unpleasant. It can actually be a sign of a leaking fuel system, a faulty emissions component, or loose parts. Many common culprits are leaking fuel lines, failing injector O-rings, work tanks and seals, or exhaust leaks. Locating the source of a gas smell is also more challenging in modern cars, as they typically capture and purge fuel vapors such that visible puddles aren’t left behind.

Regardless of the cause, addressing the smell of gas in your car as soon as possible is crucial to ensure nothing serious is amiss. Dive deeper into the common causes of gasoline smells, how to diagnose the issue, and when to contact a professional technician for assistance so that you can keep your car from malfunctioning.

How Indoor and Outdoor Fuel Smells Differ

While it may seem unimportant, smelling gas inside vs. outside of your car is a serious distinction. If you smell gas inside the passenger compartment of your car, rather than outside near the tailpipe or fuel filler, you should treat the situation seriously. Inside-cabin gasoline odors can mean vapors have migrated through the cabin vents.

A cracked intake or exhaust component may be drawing fumes into the HVAC system, or a leak under the hood could be seeping into the passenger area. Both these can present an immediate health and safety risk.

Outside gas smells, especially those that dissipate quickly, often have less urgent causes. Still, recurring or concentrated exterior fumes near the rear of the car can indicate a potential leak in the evaporative emissions (EVAP) system or a failure at the fuel tank or pump seal.

Knowing what causes gas smells, or exhaust fumes, is important as gasoline vapors are flammable and can irritate the eyes and respiratory tract. Long or repeated exposure isn’t healthy, so if the smell is strong, avoid smoking or open flames and get your vehicle inspected right away.

6 Common Causes for Gasoline Smells in Your Car

While fuel odors can stem from a range of issues under the hood and around your car, there are a handful of recurring problems seen in cars on the road today:

1. Loose, damaged, or missing gas cap: A faulty or loose gas cap allows fuel vapors to escape from the gas tank, triggering odors and often an EVAP-related check engine light.
2. EVAP system leaks or failures: The evaporative emissions system is designed to capture and recycle fuel vapors, but cracked hoses, a failing purge valve, or a saturated charcoal canister can all release gasoline fumes.
3. Fuel injector or injector O-ring leaks: Worn injector seals can allow small amounts of fuel to seep out near the engine.
4. Fuel line, rail, or pressure regulator issues: Aging rubber fuel lines, corroded metal lines, or faulty pressure regulators can release fuel under pressure, often producing noticeable odors shortly after starting the car.
5. Fuel tank or fuel pump seal problems: Small leaks at the top of the fuel tank or around the fuel pump module are harder to spot and often cause smells near the rear of the vehicle, especially after filling up.
6. Exhaust leaks mistaken for fuel odors: Exhaust leaks near the engine bay or underbody allow unburned hydrocarbons to enter the cabin, which can smell similar to gasoline and be misdiagnosed

Given the large number of potential causes for a distinct smell of gas in your car, knowing how to diagnose your vehicle and when to get professional help is crucial.

Quick Diagnosis Steps and When to Call a Pro

Given the potential health and safety risks of leaving a lingering gas smell unchecked, it’s best to learn how to diagnose the cause yourself, albeit to the extent possible. Below are some quick checks you can tackle when you notice your car smells:

1. Smell map the car: Make note of where the odor is strongest, whether at the rear (tank/EVAP area), under the hood (injectors/rails), or inside the cabin (ventilation), as the location narrows the list of suspects.
2. Check the gas cap: A loose, cross-threaded, or cracked cap is the simplest, most common cause of evaporative-system warnings and vapor odors, so visually inspect it.
3. Look for visible leaks: With the engine off and cool, inspect under the car and under the hood for wet spots, fuel stains, or the smell near lines and the tank; fuel often evaporates, so staining or a greasy film is a useful clue.
4. Scan for trouble codes: If you have an OBD-II diagnostic reader lying around your garage, check for EVAP or fuel-system codes, as a check engine light plus an EVAP code is a common pattern for vapor leaks that cause odors.
5. Sniff the dipstick and oil: Fuel-diluted oil, meaning a strong smell of excess fuel on the dipstick, can indicate leaking injectors or fuel pressure regulator problems, which is a more serious mechanical issue.

By running a self-diagnosis on your vehicle, you can either solve the issue yourself if minor or point your mechanic in the general correct direction to save them time.

To that end, knowing when to contact a professional is equally as important as knowing how to diagnose the issue and lessen the fire risk. If you notice a strong, persistent smell of gasoline inside the cabin, visible pooling, engine performance issues, or a recall alert for your vehicle referencing a fuel leak in conjunction with the smell, don’t hesitate to take your vehicle in right away.

Endurance Coverage Benefits

Repairs to fuel-system components can be expensive. Fuel pumps, injectors, pressure regulators, and associated gaskets or seals are often complicated to repair, which is why the price is high. If the cause of a gas smell in your car is related to such an issue requiring a repair, you may be on the hook for hundreds or thousands of dollars, depending on the extent of the repair.

Some vehicle service contracts or extended warranties, such as those through Endurance, list fuel-system components among covered parts. This can help cap your out-of-pocket expenses for diagnosis and repairs. Specifically, the Superior plan from Endurance offers targeted coverage for the following parts:

• Fuel delivery pump
• Diesel fuel injection pump
• Metal fuel lines
• Fuel pressure regulator
• Fuel gauge sending unit

The Supreme plan takes things a step further by offering coverage for all parts within this system, including seals and gaskets, with limited exclusions.

In addition to this coverage, Endurance plans also come with one year of Elite Benefits, in addition to standard benefits like roadside assistance. These Elite bonus perks include up to $500 in collision coverage, windshield repair, and reimbursements for up to four tires per year due to road hazards, which can help keep you on the road.

Protect Your Fuel and Exhaust System

A gasoline smell inside the car is not normal. Anytime you notice it lingering, you should start with a quick gas-cap inspection and visual check to see if anything is noticeably wrong. If you find visible leaks or notice the smell worsening, especially if on the interior, stop driving and get to a professional for an inspection right away.

Take action to protect yourself against surprise automotive costs by investing in a vehicle service contract. To learn which plan may be right for you and your vehicle, contact an Endurance representative at (800) 253-8203 or request a FREE email quote. You can also see your price right away, as well as plan recommendations, through our convenient online store.