2018 BMW 740e XDrive Smells Like Gas

Addressing Gas Smells in Your 2018 BMW 740e xDrive for Safety

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Reviewed by
Bo Fader
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 740e 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 740e 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 and diagnostic steps for a gas smell in a 2018 BMW 740e xDrive?

When addressing a gas smell in your 2018 BMW 740e xDrive, it's essential to follow a systematic diagnostic approach to ensure safety and effective resolution. Begin with a thorough visual inspection of the vehicle, focusing on the area beneath the car and around the engine compartment for any signs of fuel leaks. Next, examine the fuel lines for visible damage or leaks, as these are common sources of gas odors. Utilizing a diagnostic scanner can be beneficial in identifying any error codes related to the fuel system, which can provide valuable insights into the issue. Pay close attention to the fuel injectors, ensuring they are functioning properly and free from leaks, as a faulty injector can contribute to the gas smell. Additionally, inspect the evaporative emissions system for any potential issues, as problems here can also lead to gas odors. Finally, check the exhaust system for leaks or damage that might allow gas fumes to enter the cabin. By following this structured approach, you can effectively diagnose the source of the gas smell and take the necessary steps to resolve the issue. If you encounter difficulties or remain uncertain about any aspect of the diagnosis, seeking assistance from a qualified mechanic or BMW service center is highly recommended for professional guidance.

What could be causing a gas smell in a 2018 BMW 740e xDrive?

If you're detecting a gas smell in your 2018 BMW 740e xDrive, it's crucial to identify the underlying issue to ensure your safety and the vehicle's performance. One of the most common culprits is a fuel leak, which can occur in various parts of the fuel system, including the fuel lines or injectors. A faulty fuel injector may not atomize fuel correctly, leading to leaks and noticeable odors. Additionally, issues with the evaporative emissions system, such as a malfunctioning charcoal canister or purge valve, can also contribute to gas smells inside the cabin. Another potential source is a leak in the exhaust system, which can emit gas-like odors if components like the catalytic converter or exhaust pipes are compromised. Lastly, overfilling the gas tank can cause fuel to spill, resulting in a temporary gas smell. If you suspect any of these issues, it's advisable to conduct a thorough inspection or consult a professional mechanic to address the problem effectively.

How urgent is it to address a gas smell in a 2018 BMW 740e xDrive?

Addressing a gas smell in your 2018 BMW 740e xDrive is of utmost urgency due to the serious safety hazards it presents. Gas leaks not only heighten the risk of fire or explosion, particularly in the confined space of a vehicle, but they also pose significant health risks. Prolonged exposure to gas fumes can lead to symptoms such as dizziness, headaches, and nausea, which can escalate into more severe health issues. Moreover, neglecting this issue can result in further damage to your vehicle's components, leading to more extensive and costly repairs in the future. Therefore, it is crucial to take immediate action by consulting a qualified mechanic or contacting the manufacturer to ensure your safety and the integrity of your vehicle.

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