2016 BMW 640i XDrive Gran Coupe Smells Like Gas

Diagnosing Fuel Smell Issues in Your 2016 BMW 640i xDrive Gran Coupe and Essential Safety Measures

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Reviewed by
Andrew Hajjar
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
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45% chance it's
Something else
The most common reasons a 2016 BMW 640i 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 efficiency.
  • 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 2016 BMW 640i 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 initial checks for gas smell in a 2016 BMW 640i xDrive Gran Coupe?

When you detect a gas smell in your 2016 BMW 640i xDrive Gran Coupe, it's crucial to approach the situation methodically to ensure safety and effective diagnosis. Start by inspecting the engine bay for any visible fuel leaks, as these are often the most straightforward indicators of a problem. Pay close attention to the fuel lines and connections, as even small leaks can lead to significant odors. Next, examine the fuel pump, especially considering the history of recalls associated with BMW fuel pumps; any signs of wear or malfunction should be addressed immediately. Following this, check the fuel injectors for leaks or irregularities, as faulty injectors can contribute to the gas smell. Additionally, inspect the evaporative emissions control system, which plays a vital role in managing fuel vapors; any malfunctions here can lead to noticeable odors inside the vehicle. Lastly, don’t overlook the air intake system; ensure that the air filter and associated hoses are intact and functioning properly. By following this diagnostic approach, you can effectively identify the source of the gas smell and take the necessary steps to resolve the issue, ensuring a safer driving experience.

What are the common causes of a gas smell in a 2016 BMW 640i xDrive Gran Coupe?

When you detect a gas smell in your 2016 BMW 640i xDrive Gran Coupe, it’s essential to investigate the source promptly to ensure safety and prevent further damage. One of the first areas to check is the gas cap; a loose or damaged cap can easily lead to fuel vapors escaping, creating a noticeable odor. Make sure the cap is securely tightened and inspect it for any signs of wear or cracks. If the gas cap appears fine, the next step is to examine the fuel system for leaks. Look for any wet spots or stains under the vehicle, particularly around the fuel lines and injectors, as these can indicate a leak that requires immediate attention. Additionally, consider the emissions control system, which can also contribute to gas odors if malfunctioning. While some checks can be done at home, such as inspecting the gas cap and looking for visible leaks, it’s crucial to consult a qualified mechanic for a thorough diagnosis if the smell persists. Addressing these issues not only ensures your safety but also helps maintain the vehicle's performance and longevity.

How urgent is it to address the gas smell in my 2016 BMW 640i xDrive Gran Coupe?

Addressing a gas smell in your 2016 BMW 640i xDrive Gran Coupe is an urgent matter that should not be overlooked. The presence of a gasoline odor often signals potential issues with critical components such as fuel injectors or fuel lines, which can lead to dangerous fuel leaks. Ignoring this warning can escalate into severe safety hazards, including the risk of fire or significant engine damage. For those inclined to take a DIY approach, it is essential to first ensure your safety by working in a well-ventilated area and wearing appropriate protective gear. Begin by visually inspecting the fuel system for any signs of leaks or damage, and check the fuel injectors for proper function. However, if you are not experienced with automotive repairs, it is highly advisable to consult a qualified mechanic. Prompt action not only safeguards your vehicle but also protects your well-being and that of others on the road.

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