Mercedes-Benz GL63 AMG Smells Like Gas

Common Causes of Fuel Odors in Your Mercedes-Benz GL63 AMG and Essential Safety Measures to Take

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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 Mercedes-Benz GL63 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 Mercedes-Benz GL63 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.

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.

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.

Troubleshooting Gas Smell in a Mercedes-Benz GL63 AMG

When troubleshooting a gas smell in your Mercedes-Benz GL63 AMG, begin by inspecting the gas cap, as a loose or damaged cap is often the simplest and most common culprit. Ensure it is tightly sealed and free from cracks. If the gas cap checks out, move on to the fuel system, where you should look for any visible leaks or damage in the fuel lines, tank, and pump. Next, examine the emissions control system, as malfunctions here can also contribute to gas odors; ensure all components are functioning correctly. If the smell persists, investigate the exhaust system for leaks, which can emit strong odors outside the vehicle. Additionally, be aware of any known issues with the gas tank, particularly in certain model years, where a hole may develop on top, necessitating a replacement. Finally, check for fuel leaks under the car, especially around the gas pump area, as deteriorated hoses or connections can be significant sources of gas smells. By following this diagnostic approach, you can systematically identify and resolve the source of the gas smell, ensuring your vehicle remains safe and well-maintained.

What Could Cause a Gas Smell in a Mercedes-Benz GL63 AMG?

When you notice a gas smell in your Mercedes-Benz GL63 AMG, it's important to identify the underlying causes to ensure both your safety and the vehicle's functionality. A common culprit is a faulty gas cap, which may fail to create a proper seal, allowing fuel vapors to escape. Additionally, inspect the fuel system for potential leaks, as damaged fuel lines or a compromised fuel tank can emit strong gas odors both inside and outside the vehicle. The emissions control system is another critical component; if it is not functioning correctly, it can contribute to the gas smell. Moreover, exhaust system issues may lead to vapor escapes that create unpleasant odors. In colder temperatures, be aware that compression clamps on rubber fuel lines can loosen, resulting in leaks that may fill the cabin with gas fumes. Timely attention to these issues is vital for ensuring a safe driving experience and preserving the overall health of your Mercedes-Benz GL63 AMG.

What to Do If Your Mercedes-Benz GL63 AMG Smells Like Gas?

If your Mercedes-Benz GL63 AMG emits a gas smell, it’s crucial to act swiftly due to the potential safety hazards and risks of significant damage. Start by ensuring your safety; pull over to a secure location, turn off the engine, and allow the vehicle to cool down. Once it’s safe, inspect the area beneath your vehicle for any visible leaks around the fuel tank, fuel filter, and fuel lines. A gas smell could indicate a fuel leak, which poses a fire risk and should not be ignored. Additionally, consider the possibility of exhaust system issues, as a rich fuel mixture can lead to gas odors emanating from the exhaust. If you cannot pinpoint the source of the smell or if the problem seems complex, it’s wise to consult a professional mechanic. Engaging with online forums dedicated to the GL63 AMG can also provide valuable insights from fellow owners who have faced similar issues. Remember, regular maintenance is key to preventing such problems, ensuring both your safety and the longevity of your vehicle. Addressing these symptoms promptly can save you from costly repairs and enhance your driving experience.

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