2018 BMW I3 Smells Like Gas

Diagnosing Fuel Odor Issues in Your 2018 BMW i3 and Essential Safety Precautions

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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 BMW i3 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 BMW i3 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 initial steps to diagnose a gas smell in a 2018 BMW i3?

When diagnosing a gas smell in a 2018 BMW i3, it's crucial to follow a methodical diagnostic approach that begins with the simplest checks. Start by inspecting the area around your vehicle for any visible signs of gas leaks, such as puddles or stains, which can help you quickly identify the source of the odor. Next, ensure that the fuel cap is securely tightened, as a loose or damaged cap is a common cause of gas smells inside the cabin. After that, examine the fuel lines for any signs of damage or leaks, since compromised lines can allow gas vapors to enter the vehicle. Additionally, consider the condition of the fuel injectors, as faulty injectors may also contribute to the smell. It's also important to inspect the evaporative emissions control system, which is designed to prevent gas vapors from escaping; any malfunction in this system could lead to noticeable odors. If these initial checks do not reveal the issue, or if you feel uncertain about the next steps, consulting a qualified mechanic is advisable. They can provide a thorough inspection and accurate diagnosis, ensuring that the problem is resolved effectively. By following this structured diagnostic approach, you can efficiently address the gas smell in your BMW i3.

What could be causing a gas smell in my 2018 BMW i3?

If you're detecting a gas smell in your 2018 BMW i3, it's essential to understand the possible sources of this unusual odor, especially since the i3 is an electric vehicle. One common culprit could be leaking fluids; while the i3 doesn't use gasoline, fluids like coolant or oil can emit a smell reminiscent of gas. Inspecting under the hood and around the vehicle for any signs of leaks can be a good starting point. Additionally, a dirty or clogged cabin air filter may contribute to strange odors circulating within the car. Replacing this filter is a straightforward DIY task that can improve air quality inside your vehicle. Lastly, consider the battery and its cooling system, as issues here can also lead to unusual smells. If you're comfortable with basic automotive maintenance, checking the battery connections and ensuring the cooling system is functioning properly can help identify potential problems. However, if the smell persists or if you're unsure about any findings, it's advisable to consult a qualified mechanic to ensure your safety and the vehicle's performance.

How urgent is it to address a gas smell in a 2018 BMW i3?

When you detect a gas smell in your 2018 BMW i3, it is imperative to act swiftly. The presence of gasoline odors can signal a fuel leak, which poses a significant safety risk, including the potential for fire hazards. Ignoring this warning can lead to severe consequences, not only for the vehicle but also for the health of its occupants due to exposure to toxic fumes. It is crucial to refrain from driving the car and seek the expertise of a qualified mechanic without delay. Promptly addressing this issue not only safeguards your vehicle from further damage but also protects you and your passengers from serious health risks. Remember, the urgency of the situation cannot be overstated; taking immediate action is essential for ensuring safety and peace of mind.

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