2021 BMW M340i Problems, Recalls & Reliability
Verdict
AvoidComplaint Index
75/100
#2 most-complained of 5 M340i years
Based on NHTSA complaints per model-year, not a reliability rating. Methodology
The 2021 BMW M340i has 11 NHTSA complaints, 6 recalls, and a complaint index of 75, ranking 2nd worst of 5 model years, with a verdict of Avoid relative to other M340i years. Engine problems account for 64% of complaints.
- Complaints
- 11
- Recalls
- 6
- Crashes / fires
- 0 / 0
- Injuries / deaths
- 0 / 0
- NHTSA overall rating
- Not rated
- EPA combined MPG
- 25.5
- 22.5 city / 31.5 hwy
Top 2021 BMW M340i problems
NHTSA owner complaints by component group. Groups with 15+ complaints have their own page.
- Engine7 (64%)
- Transmission & Powertrain3 (27%)
- Electrical System2 (18%)
- Brakes1 (9%)
- Fuel System1 (9%)
- Steering1 (9%)
- Suspension, Wheels & Tires1 (9%)
What owners report
- Owners report the engine repeatedly showing excessively low oil warnings, with the issue recurring within about 1,000 miles even after a valve cover replacement.
- Some describe the B58 engine's oil pump as a known weak point, noting early versions used a plastic component before BMW switched to metal.
- One owner reported the brake pedal going to the floorboard at low speed while the transmission independently shifted through reverse, drive, and park.
- A reported engine water pump pulley failure led to coolant loss and the serpentine belt slipping off during a turn, briefly affecting steering control.
- Owners described a front-left wheel creaking noise at low speed that worsened over a month and was linked to tie rod wear.
- One owner reported a burning odor traced to a burnt 48-volt battery and negative cable after the vehicle threw drivetrain error codes.
2021 BMW M340i recalls
6 NHTSA recall campaigns list this model year.
- NHTSA 23V584000Aug 16, 2023Electrical System144 vehicles
Electrical system:software
BMW of North America, LLC (BMW) is recalling certain 2019-2022 330i, 330i xDrive, M340i, 2022 430i Coupe, 2021-2022 430i, M440i Convertible, and 2020-2022 228i xDrive Gran Coupe vehicles. The receiver audio module control unit software may fail to properly generate audible seat belt warnings to the driver to fasten their seat belt. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 208, "Occupant Crash Protection."
Risk: An audible chime that does not properly alert the driver to fasten their seat belt increases the risk of injury in a crash.
Remedy: Dealers will update the receiver audio module software, free of charge. Owner notification letters were mailed October 12, 2023. Owners may contact BMW customer service at 1-800-525-7417.
- NHTSA 23V211000Mar 29, 2023Structure & Body51 vehicles
Seats
BMW of North America, LLC (BMW) is recalling certain 2019-2021 330i, 330i xDrive, M340i xDrive, 2020-2021 X3 sDrive30i, X3 xDrive30i, X3 M40i, X3M, 2021 X3 xDrive30e, X4 xDrive30i, and X4M vehicles. The seat frame may not have been welded properly to the seat rails.
Risk: An improperly welded seat frame may not properly restrain the occupant during a crash, increasing the risk of injury.
Remedy: Dealers will replace the seat frame and back rest, free of charge. Owner notification letters were mailed May 22, 2023. Owners may contact BMW customer service at 1-800-525-7417.
- NHTSA 21V554000Jul 21, 2021Seat Belts21,537 vehicles
Seat belts
BMW of North America, LLC (BMW) is recalling certain 2021 2 Series (230i, 230i xDrive, M240i, M240i xDrive), 330e, 330e Xdrive, 4 Series Coupe (430i, 430i xDrive, M440i xDrive) M4 Coupe, M4 Competition Coupe, BMW 4 Series Convertible (430i, M440i), BMW X1 sDrive28i, xDrive28i, 2 Series Gran Coupe (228i, 228i xDrive, M235i xDrive), M2 Competition Coupe, 330i, 330i xDrive, M340i, M340i xDrive, M3, M3 Competition, 530i, 530i xDrive, 540i, 540i xDrive, MINI Hardtop 2 Door (Cooper, CooperS, JCW), X2 sDrive28i, X2 xDrive28i, X2 M35i, Z4 sDrive30i, Z4 M40i, MINI Hardtop 2 Door (Cooper SE), MINI Convertible (Cooper, Cooper S, JCW), MINI Clubman (Cooper S, Cooper S All4, JCW), MINI Countryman (Cooper, Cooper All4, Cooper S, Cooper S All4, JCW All4), Rolls Royce Ghost, MINI Countryman (Cooper S E All4), Rolls Royce Phantom, Rolls Royce Cullinan, and Toyota Supra vehicles. The passenger seat belt Automatic Locking Retractor (ALR) may deactivate early, before the webbing fully retracts. As such, these assemblies fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 208, "Occupant Crash Protection."
Risk: During a crash, a seat belt retractor that does not function as intended increases the risk of injury.
Remedy: Dealers will inspect the seat belt retractors (including the seat belts) and, if necessary, replace the retractors, free of charge. Owner notification letters were mailed on September 3, 2021. Owners may contact BMW customer service at 1-800-525-7417; 1-866-825-1525 (MINI); 1-877-877-3735 (Rolls Royce); and 1-888-270-9371 (Toyota).
2021 BMW M340i fuel economy and fuel cost
- City
- 22.5 MPG
- Highway
- 31.5 MPG
- Combined
- 25.5 MPG
- Annual fuel cost (EPA)
- $3,125
- 15,000 mi/yr
- Fuel
- Premium
- Current regular gas
- $4.32/gal
- national avg.
EPA figures; median across configurations of this model year. Estimate your own cost with the fuel cost calculator.
2021 compared with other M340i years
Frequently asked questions
- Is the 2021 BMW M340i reliable?
- NHTSA lists 11 complaints and a complaint index of 75 for the 2021 M340i, ranking it 2nd worst of 5 model years with an Avoid verdict relative to other M340i years.
- What is the biggest problem area for the 2021 BMW M340i?
- Engine complaints make up 64% of all reported issues, the largest share of any problem area for this model year.
- Does the 2021 BMW M340i have any recalls?
- NHTSA lists 6 recalls for the 2021 M340i, covering the electrical system, structure and body, seat belts, and collision avoidance cameras, none of which are do-not-drive recalls.
- At what mileage do 2021 M340i problems typically appear?
- The median mileage at failure reported to NHTSA for Transmission & Powertrain and Brakes complaints is 4,000 miles.
- How does the 2021 M340i compare to the 2020 M340i?
- The 2020 M340i has a higher complaint index of 100 with 53 complaints and is also rated Avoid, while the 2021 model has a complaint index of 75 with 11 complaints.