2014 Mercedes-Benz E400 Smells Like Gas

Diagnosing Fuel Smells in Your 2014 Mercedes-Benz E400: Causes and Solutions for a Safe Drive

Find Repair Location
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 2014 Mercedes-Benz E400 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 2014 Mercedes-Benz E400 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 the gas smell in my 2014 Mercedes-Benz E400, and what diagnostic steps should I take first?

When you detect a gas smell in your 2014 Mercedes-Benz E400, it's crucial to approach the diagnosis methodically. Start with a visual inspection of the vehicle, looking for any obvious signs of fuel leaks around the fuel lines and engine compartment. A common culprit can be a loose or damaged fuel cap, so ensure it is securely fastened to prevent fuel vapors from escaping. Next, inspect the exhaust system for any visible damage or leaks, as issues like a cracked manifold or faulty catalytic converter can also contribute to the odor. If these initial checks do not reveal the source of the problem, consider using a diagnostic scanner to identify any error codes related to the fuel system or emissions components. This step can provide valuable insights into underlying issues that may not be immediately visible. If you are still unable to determine the cause of the gas smell after these steps, it is advisable to consult a qualified mechanic for a comprehensive inspection. By following this structured diagnostic approach, you can effectively identify and address the source of the gas smell, ensuring both your safety and the proper functioning of your vehicle.

What could be causing a gas smell in my 2014 Mercedes-Benz E400?

If you notice a gas smell in your 2014 Mercedes-Benz E400, it’s crucial to investigate the underlying causes to ensure both safety and vehicle performance. One of the most common issues is a fuel leak, which can occur from various components such as fuel injectors, fuel lines, or even the fuel tank itself. Inspect these areas for any signs of wetness or damage. Additionally, a faulty or loose fuel cap can lead to fuel vapors escaping, so check that it is secure and in good condition. Another potential culprit is the evaporative emissions system, which manages fuel vapor release; any malfunction here can result in noticeable odors. Furthermore, consider the exhaust system, as leaks near the engine compartment can allow gas smells to infiltrate the cabin. Lastly, engine performance issues, such as running too rich, can also contribute to a gas smell. If you are unable to pinpoint the source of the odor after your inspection, it is advisable to consult a qualified mechanic for a thorough diagnosis and repair.

How urgent is it to address the gas smell in my 2014 Mercedes-Benz E400?

Addressing a gas smell in your 2014 Mercedes-Benz E400 is not just a matter of comfort; it is a critical safety issue that demands immediate attention. The presence of gasoline odors inside your vehicle can signal a fuel leak, which poses a significant fire hazard that could endanger you and your passengers. Additionally, inhaling gasoline fumes can lead to serious health risks, including headaches, dizziness, and nausea, making it essential to resolve the issue quickly. Ignoring this warning sign can also result in more severe mechanical problems down the line, potentially leading to costly repairs. Therefore, if you detect a gas smell, it is imperative to investigate the source promptly, ensuring both your safety and the longevity of your vehicle. Taking swift action not only protects you but also helps maintain the performance and reliability of your Mercedes-Benz E400.

You’ve got options with RepairPal

Whether you need a more accurate auto repair estimate or help finding a reputable shop in your area, we’ve got you covered.