2018 Cadillac XTS Smells Like Gas

Identifying Potential Causes of Gas Smells in Your 2018 Cadillac XTS and Essential Safety Measures

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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 2018 Cadillac XTS 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 Cadillac XTS 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 are the potential causes and diagnostic steps for a gas smell in a 2018 Cadillac XTS?

When dealing with a gas smell in your 2018 Cadillac XTS, it's essential to adopt a systematic diagnostic approach to identify the underlying issue effectively. Start by inspecting the vehicle for any visible fuel leaks, as these can often be the most straightforward cause of the odor. Pay particular attention to areas around the fuel injectors, fuel lines, and the fuel tank. Next, check the fuel cap to ensure it is securely tightened; a loose or damaged cap can allow gas vapors to escape, leading to a noticeable smell. If these initial checks do not reveal the problem, consider using a diagnostic scanner to look for error codes that may indicate issues with the fuel system or the evaporative emissions system. Inspect components such as the charcoal canister and purge valve for any signs of damage or leaks, as these can also contribute to gas odors. Additionally, examine the exhaust system for any leaks or cracks that might be causing the smell. Finally, monitor the engine's performance for any irregularities, such as rough idling or decreased fuel efficiency, which could signal a more complex issue. By following this structured approach, you can effectively diagnose and address the source of the gas smell in your Cadillac XTS.

What could be causing a gas smell in my 2018 Cadillac XTS?

If you're experiencing a gas smell in your 2018 Cadillac XTS, it's essential to understand the potential causes to address the issue effectively. One of the primary reasons for a gas odor is a fuel leak, which can originate from the fuel tank, fuel lines, or fuel injectors. Additionally, a malfunctioning fuel injector that fails to atomize fuel properly can contribute to the smell. Another area to investigate is the evaporative emissions system; issues such as a faulty charcoal canister or purge valve can lead to gas vapors escaping into the vehicle's interior. It's also worth checking for leaks in the exhaust system, particularly around the catalytic converter or muffler, as these can sometimes produce a gas-like odor. Lastly, if you've recently overfilled your gas tank, this could result in fuel spillage and a temporary gas smell. While some of these issues can be diagnosed through DIY methods, it's crucial to consult a professional mechanic for a comprehensive inspection to ensure your safety and the proper functioning of your vehicle.

How urgent is it to address the gas smell in my 2018 Cadillac XTS?

Addressing a gas smell in your 2018 Cadillac XTS is not just a matter of inconvenience; it is an urgent safety concern that requires immediate attention. The presence of gasoline odors can signal a fuel leak, which poses a significant fire risk and could lead to catastrophic consequences if not resolved quickly. Moreover, inhaling gasoline fumes can adversely affect your health, leading to symptoms such as headaches, dizziness, and nausea, which can escalate with prolonged exposure. Ignoring this issue not only jeopardizes your well-being but can also result in further damage to your vehicle, leading to more extensive and costly repairs down the line. Therefore, if you detect a gas smell, it is imperative to investigate the source and address it without delay to ensure your safety and the longevity of your Cadillac XTS.

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