2018 BMW M140i
The 2018 BMW M140i is a performance-oriented hatchback celebrated for its powerful engine, engaging driving dynamics, and practical size. The primary engine option is the B58 3.0-liter turbocharged inline-six, producing around 335 horsepower and 369 lb-ft of torque. It was available with either an 8-speed automatic or a 6-speed manual transmission in certain markets. Owners often praise its impressive acceleration, nimble handling, and the overall fun-to-drive factor. However, some common complaints include the relatively firm ride (especially on models with the adaptive suspension), the cost of maintenance and repairs, and the somewhat dated interior compared to newer models.
Engine
B58 3.0L Turbocharged Inline-Six
- Oil Filter Housing/Cooler Leaks
- Description/Symptoms: Coolant and/or oil leaks are found near the oil filter housing. The leaks can range from small seeps to more significant drips. Can cause overheating if coolant levels drop.
- Solution: Replacement of the oil filter housing gasket and potentially the entire housing if warped or damaged.
- Estimated Cost to Fix: $300 - $800+ depending on whether just the gasket is replaced or the entire housing.
- Recalls: None Found
- VANOS Solenoid Issues
- Description/Symptoms: Engine performance issues, including rough idling, hesitation upon acceleration, and potential for the engine to stall. Diagnostic codes related to VANOS (Variable Valve Timing) system malfunction are often present.
- Solution: Replacement of the faulty VANOS solenoid(s). An oil change is also advised, to check for any metal shavings.
- Estimated Cost to Fix: $200 - $600+ per solenoid, depending on labor and parts cost.
- Recalls: None Found
- Coolant Leaks (various locations)
- Description/Symptoms: Coolant leaks from various locations on the engine. The most common areas for coolant leaks on the B58 are the plastic coolant pipes running along the left side of the engine and the water pump. Other areas can include coolant hoses and the radiator.
- Solution: For coolant pipes, replace the plastic pipes with aluminum ones. For other areas, replace leaking hoses, gaskets, or components.
- Estimated Cost to Fix: $100 - $1000+ depending on the severity and location of the leak.
- Recalls: None Found
Transmission
8-Speed Automatic (ZF 8HP)
- Rough Shifting/Hesitation
- Description/Symptoms: Noticeable harsh or jerky shifts, especially between certain gears. Hesitation or delay when shifting gears. This can sometimes be exacerbated when the transmission is cold.
- Solution: A transmission fluid change is advised first. If this doesn’t solve the issue, valve body issues are suspected and replacement or rebuild of the valve body is required. Some owners also perform a transmission software reflash.
- Estimated Cost to Fix: $300-$1000+ fluid change, $1500 - $3000+ for valve body work.
- Recalls: None Found
- Mechatronic Unit Failure
- Description/Symptoms: Limp mode, inability to shift, and diagnostic trouble codes related to the mechatronic unit (the electronic control unit inside the transmission).
- Solution: Replacement or rebuild of the mechatronic unit.
- Estimated Cost to Fix: $2000 - $4000+
- Recalls: None Found
6-Speed Manual
No Issues Found
Suspension
- Adaptive Damper Issues (if equipped)
- Description/Symptoms: Uneven ride, knocking sounds from the suspension, error messages related to the adaptive dampers. One or more dampers may fail, leading to a noticeable difference in ride quality from one side of the car to the other.
- Solution: Replacement of the faulty adaptive damper(s).
- Estimated Cost to Fix: $500 - $1500+ per damper, including labor.
- Recalls: None Found
- Rear Subframe Bushings
- Description/Symptoms: Clunking or knocking noises from the rear of the vehicle, especially when going over bumps or accelerating/decelerating abruptly. Vague handling and instability during cornering.
- Solution: Replacement of the worn rear subframe bushings. Uprated bushings may improve handling performance.
- Estimated Cost to Fix: $500-$1000+
- Recalls: None Found
Electrical
- Infotainment System Glitches
- Description/Symptoms: Freezing, crashing, or lagging of the iDrive infotainment system. Connectivity issues with Bluetooth or other devices.
- Solution: Software updates or, in some cases, replacement of the iDrive control unit.
- Estimated Cost to Fix: $0 (if software update resolves it) - $1000+ for control unit replacement.
- Recalls: None Found
- Battery Drain Issues
- Description/Symptoms: The battery drains quickly, especially when the car is not driven for extended periods. Can lead to difficulty starting the car.
- Solution: Diagnosis to identify the parasitic draw. Common culprits include faulty modules or aftermarket accessories. Repair or replacement of the offending component.
- Estimated Cost to Fix: $100 - $1000+ depending on the source of the drain.
- Recalls: None Found
- Steering Rack
- Description/Symptoms: Occasional malfunction of the steering rack, where the steering wheel requires excessive force to turn the wheel.
- Solution: Full steering rack replacement.
- Estimated Cost to Fix: $2000+
- Recalls: None Found
Exterior
- Cracked Washer Fluid Reservoir
- Description/Symptoms: Leaking washer fluid, usually from the bottom of the reservoir.
- Solution: Replacement of the washer fluid reservoir.
- Estimated Cost to Fix: $100 - $300+
- Recalls: None Found
Interior
- Seat Heater Failure
- Description/Symptoms: Seat heater not working or working intermittently. This can often be attributed to a break in the heating element within the seat.
- Solution: Replacement of the seat heating element or repair of the wiring.
- Estimated Cost to Fix: $300 - $800+ depending on repair vs replacement.
- Recalls: None Found
Summary
The 2018 BMW M140i, while generally reliable, can experience issues related to its engine, transmission, suspension, and electrical systems. The most significant concerns revolve around potential oil leaks, transmission issues (especially with the automatic), and problems with the adaptive dampers. Repair costs can vary widely, but certain issues, like mechatronic unit failure or adaptive damper replacement, can be quite expensive. Early detection and preventative maintenance are key to mitigating potential problems and ensuring the longevity of this performance hatchback.