2018 Mercedes-Benz G65 AMG Smells Like Gas

Diagnosing Fuel Odor Issues in Your 2018 Mercedes-Benz G65 AMG 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
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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 2018 Mercedes-Benz G65 AMG 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 Mercedes-Benz G65 AMG 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.

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.

When the fuel filter begins to clog, the engine suffers from fuel starvation. This will cause a significant reduction in power and may also cause a misfire. These conditions may be intermittent, or constant and worsen over time. As the issue progresses, the engine may being to stall immediately after starting, fail to start, hesitate under throttle, or stall at particular angles on hills.

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 for a gas smell in a 2018 Mercedes-Benz G65 AMG, and how should I diagnose the issue?

When faced with a gas smell in your 2018 Mercedes-Benz G65 AMG, it's essential to approach the diagnosis methodically, starting with the simplest potential causes before moving on to more complex issues. Begin by inspecting the fuel cap; ensure it is securely fastened and free from damage, as a loose or faulty cap can easily allow gas vapors to escape. Next, check for any visible fuel leaks around the fuel tank and lines, as these can indicate a more serious problem that requires immediate attention. If these initial checks do not reveal the source of the smell, turn your focus to the evaporative emissions system, which can malfunction and lead to gas fumes escaping. Additionally, examine the exhaust system for any leaks or damage, particularly around the catalytic converter, as these can also contribute to a gas odor. Finally, consider potential engine issues, such as a rich fuel mixture or faulty sensors, which may necessitate a diagnostic scan to uncover underlying problems. By following this structured approach, you can effectively narrow down the cause of the gas smell and determine whether a simple fix or professional assistance is required.

What could be causing a gas smell in my 2018 Mercedes-Benz G65 AMG?

If you're detecting a gas smell in your 2018 Mercedes-Benz G65 AMG, 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-like smells 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, may also be responsible for the unpleasant odor. 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 2018 Mercedes-Benz G65 AMG?

Addressing a gas smell in your 2018 Mercedes-Benz G65 AMG is of utmost urgency due to the serious safety risks it poses. Gas leaks can lead to catastrophic outcomes, including fire or explosion, especially in the confined space of a vehicle. Moreover, inhaling gas fumes can have detrimental effects on your health, causing symptoms like dizziness and nausea, which can escalate with prolonged exposure. Ignoring this warning sign not only jeopardizes your safety but can also result in significant damage to your vehicle, leading to expensive repairs down the line. Therefore, if you detect a gas smell, it is imperative to stop driving immediately and consult a qualified mechanic to diagnose and rectify the issue. Taking swift action is essential to safeguard your well-being and maintain the integrity of your vehicle.

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