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2018 BMW i3

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By Research the Car 4 min read

The 2018 BMW i3 is a quirky and innovative electric hatchback, known for its distinctive styling, lightweight carbon fiber reinforced plastic (CFRP) construction, and surprisingly spacious interior. The standard i3 features a 33 kWh battery powering an electric motor producing 170 horsepower and 184 lb-ft of torque. An optional range extender (REx) model includes a small 647cc two-cylinder gasoline engine (38 hp) that doesn’t directly power the wheels but acts as a generator to extend the driving range. People appreciate the i3’s nimble handling, eco-friendly nature, and unique design. Common dislikes include its limited range (especially on pre-2019 models), firm ride, and polarizing styling.

Electric Motor

Standard Electric Motor

  • Reduced Battery Capacity Over Time
    • Description/Symptoms: Owners report a gradual decrease in battery capacity over several years, resulting in a reduced driving range compared to the original EPA-estimated range. The actual amount of degradation varies depending on factors like driving habits, climate, and charging frequency.
    • Solution: There is no fix for this. Battery degradation is a normal occurrence in electric vehicles.
    • Estimated Cost to Fix: N/A
    • Recalls: None Found
  • High Voltage Battery Failure
    • Description/Symptoms: Complete failure of the high-voltage battery, resulting in the vehicle being unable to start or drive. This is a less common but more serious issue.
    • Solution: Replacement of the high-voltage battery.
    • Estimated Cost to Fix: $15,000+
    • Recalls: None Found

Range Extender (REx) Engine

  • Faulty Fuel Level Sensor
    • Description/Symptoms: Inaccurate fuel level readings in the REx fuel tank, leading to the range extender not activating when needed or shutting down prematurely.
    • Solution: Replacement of the fuel level sensor.
    • Estimated Cost to Fix: $300 - $500
    • Recalls: None Found
  • Reduced Engine Power Error with REx
    • Description/Symptoms: A “Reduced Engine Power” warning light may appear on the dashboard, indicating that the range extender engine is not functioning at full capacity. This could be due to various issues, such as a faulty oxygen sensor, a clogged fuel filter, or issues with the engine’s control system.
    • Solution: Diagnosis and repair of the specific issue causing the reduced engine power. This may involve replacing faulty sensors, cleaning or replacing fuel filters, or reprogramming the engine control unit (ECU).
    • Estimated Cost to Fix: $200 - $1000+ (depending on the specific issue)
    • Recalls: None Found

Electrical

  • 12V Battery Drain
    • Description/Symptoms: The 12V auxiliary battery can drain quickly, especially if the car is left unused for extended periods. This can prevent the car from starting or operating certain features.
    • Solution: Regular trickle charging of the 12V battery when the car is not in use or replacement with a new battery. Some owners have also identified parasitic drains caused by aftermarket accessories or faulty modules.
    • Estimated Cost to Fix: $150 - $300 (battery replacement), $100+ (diagnosis of parasitic drain)
    • Recalls: None Found
  • Charging Port Issues
    • Description/Symptoms: Difficulty charging the vehicle, including failure to recognize the charging cable, slow charging speeds, or error messages during charging. This can be caused by a faulty charging port, issues with the charging cable, or problems with the car’s charging system.
    • Solution: Diagnosis of the charging system and replacement of the faulty component, such as the charging port or onboard charger.
    • Estimated Cost to Fix: $300 - $1000+ (depending on the component)
    • Recalls: None Found

Exterior

  • Tail Light Failure
    • Description/Symptoms: LED tail lights may experience partial or complete failure, requiring replacement of the entire tail light assembly. This is a known issue with some BMW models.
    • Solution: Replacement of the faulty tail light assembly.
    • Estimated Cost to Fix: $400 - $800+ per side
    • Recalls: None Found

Interior

  • iDrive Screen Malfunctions
    • Description/Symptoms: The iDrive infotainment screen may freeze, glitch, or become unresponsive. In some cases, the screen may flicker or display distorted images.
    • Solution: A software update may resolve some of these issues. In more severe cases, the iDrive control unit may need to be replaced.
    • Estimated Cost to Fix: $0 (software update) - $1000+ (control unit replacement)
    • Recalls: None Found
  • Sunroof Issues
    • Description/Symptoms: Sunroof may be erratic, noisy, or gets stuck when opening or closing.
    • Solution: Apply lubrication, realign tracks, or replace sunroof motor.
    • Estimated Cost to Fix: $100 - $800+
    • Recalls: None Found

Summary

The 2018 BMW i3 is generally a reliable electric vehicle, but like any car, it has its share of common issues. The most concerning are the potential for high-voltage battery degradation and failure, which can be very costly to repair. Other electrical issues, such as 12V battery drain and charging port problems, are also relatively common. The range extender engine, while helpful for increasing range, can also introduce its own set of problems. The iDrive screen malfunctions can be annoying but are usually fixable with software updates. Potential buyers should be aware of these issues and factor them into their purchasing decision. A pre-purchase inspection by a qualified mechanic is highly recommended, especially for checking the health of the high-voltage battery.

BMW, i3
BMW i3 2018
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