2018 BMW 650i XDrive Smells Like Gas

Addressing Gas Smells in Your 2018 BMW 650i xDrive for Safety

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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
0%
40% chance it's the
Emissions Control System
0%
45% chance it's
Something else
The most common reasons a 2018 BMW 650i 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 2018 BMW 650i 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 initial steps to diagnose a gas smell in a 2018 BMW 650i xDrive?

When diagnosing a gas smell in your 2018 BMW 650i xDrive, it's crucial to follow a methodical diagnostic approach that emphasizes safety and thoroughness. Begin by inspecting the area around your vehicle for any visible signs of fuel leaks, such as puddles or wet spots, which can indicate a serious issue that needs immediate attention. Next, examine the fuel lines and connections under the hood for any signs of wear, damage, or loose fittings that could be contributing to the odor. It's also important to check the fuel tank for any leaks or damage that might allow gas fumes to escape. Additionally, consider the condition of the fuel injectors, as a malfunctioning injector could be the source of the smell. Don't forget to inspect the evaporative emissions control system, as issues in this area can also lead to gas odors. If your initial checks do not reveal the source of the smell, or if you suspect a more complex issue, it is advisable to consult a qualified mechanic or a BMW dealership for a comprehensive diagnosis and repair. By following this structured approach, you can effectively identify and address the gas smell in your vehicle, ensuring both safety and optimal performance.

What are the common causes of a gas smell in a 2018 BMW 650i xDrive?

When you detect a gas smell in your 2018 BMW 650i xDrive, it’s crucial to understand the common problems that could be at play. One of the primary culprits is a fuel leak, which can stem from damaged fuel lines, faulty fuel injectors, or even a compromised fuel tank. Additionally, a loose or damaged fuel cap can allow gas vapors to escape, creating an unpleasant odor both inside and outside the vehicle. Another area to investigate is the evaporative emissions control system; issues with components like the charcoal canister or purge valve can lead to gas smells as well. Furthermore, don’t overlook the exhaust system, as leaks from the exhaust manifold or a damaged catalytic converter can also contribute to the issue. Lastly, engine problems such as a rich fuel mixture or malfunctioning sensors may result in a gas odor in the cabin. Addressing these issues promptly is essential for safety, 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 2018 BMW 650i xDrive?

When you detect a gas smell in your 2018 BMW 650i xDrive, it is essential to act swiftly due to the serious safety risks involved. A gasoline odor often signals a fuel leak, which can lead to fire hazards and poses a significant threat to both your safety and that of others on the road. Additionally, inhaling gasoline fumes can result in health issues, including dizziness and nausea, making it imperative to address the situation without delay. Ignoring this warning can escalate into more severe problems, such as engine damage or costly repairs. For those inclined to take a DIY approach, it is crucial to stop driving the vehicle immediately and conduct a thorough inspection of the fuel system, including checking for leaks around the fuel lines and connections. If you are unsure or unable to identify the source of the smell, seeking assistance from a professional mechanic is highly recommended to ensure your safety and the integrity of your vehicle.

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