2020 BMW M240i XDrive Smells Like Gas

Common Causes of Fuel Odors in Your 2020 BMW M240i xDrive and How to Address Them Safely

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Reviewed by
Devin Cabugcal
Written by RepairPal Car Genius
Updated January 14, 2025
0%
15% chance it's the
Gas Cap
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40% chance it's the
Emissions Control System
0%
45% chance it's
Something else
The most common reasons a 2020 BMW M240i xDrive smells like gas are the gas cap, the fuel system, or the emissions control system.
  • Gas Cap: A loose or damaged gas cap can cause fuel vapors to escape, triggering the check engine light and potentially affecting fuel system pressure.
  • Emissions Control System: A faulty emissions control system can lead to increased hydrocarbon emissions and trigger the check engine light due to malfunctioning components like the EGR valve or O2 sensors.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 2020 BMW M240i xDrive smells like gas?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

A failing catalytic converter can cause a vehicle to fail emissions tests and turn on the check engine light. The exhaust might have an unusual smell. A restricted catalytic converter can result in a loss of engine power.

» LEARN MORE: How to tell if your catalytic converter is failing

The check engine light will illuminate any time there is a failed EVAP system test. This will be indicated by the various on-board diagnostics trouble codes that are stored in the vehicle's memory. Also, in some models, there may be a popping sound accompanying the check engine light, as the leak detection pump continuously attempts to pressurize the fuel tank. The canister may also cause difficulty starting the engine, a rough idle, and poor fuel mileage.

The check engine light will illuminate any time there is a failed EVAP system test. This will be indicated by the various on-board diagnostics trouble codes that are stored in the vehicle's memory. Also, in some models, there may be a popping sound accompanying the check engine light, as the leak detection pump continuously attempts to pressurize the fuel tank. A fuel tank leak may also cause difficulty starting the engine, a rough idle, and poor fuel mileage. When a fuel tank is simply corroded to the point of failure, the exterior tank condition rarely shows damage. The inside of the fuel tank will be rusted or corroded, and rust flakes or other debris may be floating in the fuel.

For most vehicles, the only symptom will be a check engine light or fuel tank filler cap light illuminating on the driver instrument cluster. This is to signal that there is an evaporative emissions (EVAP) leak. In some situations, the vehicle may take longer than normal to start, or, more rarely, the engine may not start at all. on-board diagnostic (OBD) trouble codes will refer to EVAP system failures such as a small or massive EVAP system leak. Lastly, the powertrain control module may notice a lean running condition, which could even lead to random and infrequent misfires.

What are the potential causes of a gas smell in a 2020 BMW M240i xDrive, and how should I diagnose the issue?

When diagnosing a gas smell in your 2020 BMW M240i xDrive, it's essential to adopt a systematic approach that begins with the simplest potential causes before moving on to more complex issues. Start by checking for fuel leaks in the fuel system, including the fuel lines, tank, and injectors, as any visible signs of leakage can be a straightforward fix. Next, examine the fuel cap to ensure it is tightly sealed; a loose or damaged cap is a common culprit for gas odors. If these initial checks do not resolve the issue, inspect the Evaporative Emission Control System (EVAP), which is crucial for containing fuel vapors. Look for any faults in components like the charcoal canister or purge valve. Additionally, consider the exhaust system, as leaks from the exhaust manifold or a damaged catalytic converter can also produce a gas smell. Finally, if the problem persists, it may be necessary to investigate the engine itself for issues such as malfunctioning fuel injectors or an overly rich fuel mixture. While these steps can guide you in your DIY diagnosis, consulting a qualified mechanic or BMW dealership is advisable for a thorough assessment and repair recommendations.

What could be causing a gas smell in my 2020 BMW M240i xDrive?

If you're detecting a gas smell in your 2020 BMW M240i xDrive, it's crucial to understand the common problems that could be at play. One of the primary concerns is a fuel leak, which may stem from damaged fuel lines, faulty fuel injectors, or issues with the fuel tank itself. Additionally, the evaporative emissions system, designed to manage fuel vapors, can malfunction and contribute to the odor. Exhaust system problems, such as leaks or a failing catalytic converter, can also allow gas fumes to infiltrate the cabin. Overfilling the gas tank is another simple yet often overlooked cause, as it can lead to fuel spillage. Lastly, faulty engine components, including the fuel pressure regulator or injectors, may be responsible for the smell. Addressing these issues promptly is essential for both safety and vehicle performance, and while some DIY diagnostics can be performed, consulting a qualified mechanic is advisable for a thorough inspection and resolution.

How urgent is it to address a gas smell in a 2020 BMW M240i xDrive?

Addressing a gas smell in your 2020 BMW M240i xDrive is not just a matter of convenience; it is an urgent safety concern that should never be overlooked. Gas leaks can lead to catastrophic outcomes, including fires or explosions, making immediate action essential. Furthermore, inhaling gas fumes poses serious health risks, with symptoms ranging from dizziness and nausea to more severe complications with prolonged exposure. Ignoring this warning sign can also result in significant damage to your vehicle's components, leading to expensive repairs down the line. Therefore, if you detect a gas smell, it is crucial to seek professional assistance without delay to ensure both your safety and the optimal performance of your car.

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