2020 BMW 440i XDrive Gran Coupe Smells Like Gas

Diagnosing Fuel Smells in Your 2020 BMW 440i xDrive Gran Coupe and Essential Safety Precautions

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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 2020 BMW 440i xDrive Gran Coupe 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 440i xDrive Gran Coupe 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 could be causing a gas smell in a 2020 BMW 440i xDrive Gran Coupe, and what diagnostic steps should be taken first?

When you notice a gas smell in your 2020 BMW 440i xDrive Gran Coupe, it's essential to diagnose the issue systematically to ensure both safety and effective resolution. Begin with a careful visual inspection of the vehicle, particularly under the car and around the fuel tank, looking for any signs of fuel leaks, such as wet spots or a strong odor. Next, turn your attention to the fuel injectors; a malfunctioning injector can lead to fuel leakage, so check for any visible damage or leaks. Additionally, inspect the evaporative emissions system, which is crucial for preventing fuel vapors from escaping; any faults in this system could contribute to the gas smell. It's also important to examine the exhaust system, as leaks here can sometimes produce a gas-like odor; look for any holes or signs of damage. Finally, utilizing a diagnostic scanner to check for error codes related to the fuel system or emissions components can provide valuable insights into the underlying issue. By following these diagnostic steps, you can effectively identify the source of the gas smell and take the necessary actions to address it.

What are the common causes of a gas smell in a 2020 BMW 440i xDrive Gran Coupe?

If you detect a gas smell in your 2020 BMW 440i xDrive Gran Coupe, it’s crucial to understand the common problems that could be at play. One of the primary concerns is a fuel leak, which can pose serious safety risks and should be investigated immediately. Additionally, a faulty fuel injector may be leaking fuel, leading to the odor, while issues with the fuel tank, such as cracks or leaks, can also contribute to the smell. Another potential culprit is the evaporative emissions system; components like the charcoal canister or purge valve may malfunction, resulting in gas odors. Lastly, don’t overlook the exhaust system, as leaks or damage to parts like the catalytic converter can sometimes allow gas fumes to enter the cabin. Addressing these issues promptly is essential for both safety and vehicle performance, so if you notice a gas smell, consider a thorough inspection or consult a qualified mechanic.

How urgent is it to address a gas smell in a 2020 BMW 440i xDrive Gran Coupe?

Addressing a gas smell in your 2020 BMW 440i xDrive Gran Coupe is not just a matter of inconvenience; it is a pressing safety concern that requires immediate attention. Gas leaks pose significant risks, including the potential for fire or explosion, which can have devastating consequences. Additionally, inhaling gas fumes can lead to serious health issues, such as dizziness, headaches, and nausea, particularly with prolonged exposure. Beyond the immediate dangers, neglecting a gas smell can result in further damage to your vehicle, leading to more extensive and expensive repairs down the line. Therefore, it is essential to take any gas odor seriously and act swiftly to ensure your safety, protect your health, and maintain the integrity of your vehicle.

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Why Your 2020 BMW 440i xDrive Smells Like Gas | RepairPal