2020 BMW M340I Problems
Owner-reported complaints filed with NHTSA, grouped by component
Data refreshed
What this page shows
Everything below is an owner-reported complaint submitted to NHTSA about the 2020 BMW M340I, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Reports by component
Ranked by how many owner reports name each component category
- Engine3972.2%
- Electrical611.1%
- Fuel system35.6%
- Powertrain (other)23.7%
- Tires & wheels23.7%
- Brakes11.9%
- Other / unspecified11.9%
Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.
Each component in detail
What the reports in each category say, in the owners' own words
Engine
Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components.
From owner reports, verbatim
Component Involved:Engine Mechanical / Variable-Displacement Engine Oil Pump (Part #11418635032 / Updated #11419895359) Description of Safety Hazard / Defect:The early-generation B58TU engine features a variable-displacement oil pump equipped with an internal thermoplastic (plastic) adjusting ring. Due to continuous thermal cycling and mechanical stress, this plastic ring is prone to cracking and shattering without warning.When this internal component disintegrates, it causes an immediate loss of oil pressure to critical engine components. This creates a severe safety hazard, as the vehicle can experience a sudden loss of motive power or complete engine seizure while travelling at highway speeds, placing the occupants and surrounding traffic at immediate risk of a collision.Furthermore, a known software bug or sensor interference tied to this specific mechanical failure prevents the iDrive system from successfully completing an electronic oil level measurement, thereby masking the impending failure from the driver until catastrophic engine failure occurs.Relevance of International Actions:In May 2026, BMW Korea officially acknowledged this identical component design flaw by launching a proactive, free preventative repair campaign for B58TU engines manufactured between January 2019 and June 2021. BMW is actively replacing the defective plastic-ring oil pumps with an updated, all-metal version in that market.North American consumers are driving vehicles equipped with the exact same defective part, manufactured during the same window, and facing the same catastrophic safety risks. I am requesting that the agency open a formal defect investigation into BMW North America to mandate a safety recall or an extended component warranty program.
Safety Hazard: Oil Pump Failure Leading to Sudden Engine Stall (BMW B58TU engines) Description of Defect: The oil pump module in the 2020 BMW M340i (G20) and many other models between 2019-2020 contains internal plastic components that are prone to thermal degradation and premature failure. These plastic parts can crack or disintegrate, causing a sudden loss of oil pressure. BMW corrected this in later models with metal parts but failed to issue a recall or the older models containing plastic parts. Safety Risk: A failure of the oil pump leads to insufficient lubrication of critical engine components, which can result in a sudden and complete engine seizure while the vehicle is in motion. This causes an immediate loss of propulsion and power steering assist, significantly increasing the risk of a high-speed collision or being stranded in dangerous traffic conditions. Additional Note: This is a known mechanical defect where a critical engine component (oil pump) relies on non-durable plastic materials, creating an unreasonable safety risk for drivers and passengers due to potential catastrophic engine failure without prior warning.
Electrical
Reports naming the electrical system — wiring, battery, charging, control modules, infotainment and electrical accessories.
From owner reports, verbatim
The ignition start is not clean and delayed. There is already a recall 25V-644. There is "No remedy available" for this model per inquiry with local BMW dealer in Buffalo NY 14221 made 3 weeks ago. I am fearful of an electrical fire from overheating. I do smell an intermittent burning smell but it may in the outside environment rather than from under my hood.
The contact owns a 2020 BMW M340I. The contact stated that the vehicle was repaired under NHTSA Campaign Number: 24V576000 (Electrical System, Engine and Engine Cooling); however, the repair failed to prevent the failure from occurring. The contact stated that shortly after the recall repair was completed, the vehicle hesitated to start. The contact stated that several employees at the local dealer attempted to start the vehicle. The vehicle started; however, several months later, the failure reoccurred. An appointment with the dealer was scheduled to inspect the vehicle. The vehicle was not repaired and needed to be towed. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 28,162.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Fuel system
Reports naming fuel storage or delivery — tanks, pumps, lines, injectors and fuel leaks.
From owner reports, verbatim
My vehicle doesn’t read the oil level since the fuel pump that BMW used to manufacture the car is made out of plastic material. There has been hundred of complaints about the same issue with the oil pump not working properly due to the fact that BMW used plastic instead of metal etc. I would like for the NHTSA to take a look at this issue and please consider making it a recall for the users that are having this “Oil Pump” issue please thank you.
Unable to read oil level, high or unusually alarming oil pressure. High oil pressure codes
Too few reports in this category for a page of its own — they appear in the full complaint list.
Powertrain (other)
Powertrain reports that are not specifically the engine or transmission — driveshafts, axles, transfer cases and differentials.
From owner reports, verbatim
Component: Front differential / xDrive drivetrain system. Vehicle is available for inspection upon request. Description: My 2020 BMW M340i xDrive has exhibited a persistent whining noise from the front drivetrain since approximately 38,000 miles. The noise varies with speed and load and appears to originate from the front differential. A BMW dealership inspected the vehicle and acknowledged the noise but declined repair under warranty. This condition is consistent with premature wear of internal differential components such as gears or bearings, or improper lubrication. Differentials should not produce whining noises at this mileage, indicating a potential defect. Safety Risk: The front differential is critical to torque distribution in the all wheel drive system. Progressive failure could result in drivetrain binding, uneven torque delivery, or loss of AWD functionality. In a worst case scenario, partial or full differential seizure could occur, leading to sudden resistance, instability, or loss of control. These risks are heightened at highway speeds or in low traction conditions such as rain or snow. The vehicle provides no warning lights or messages despite the abnormal condition, meaning failure could occur without advance notice. Inspection: Issue confirmed by BMW dealership. No repair or corrective action performed. Warnings/Symptoms: No warning lights or system messages. Only symptom is a persistent whining noise from the front drivetrain. Additional Information: I am aware of similar complaints from other BMW xDrive owners reporting drivetrain whining, grinding, and vibration, suggesting a broader pattern of premature differential wear.
My oil pump went out causing Low pressure codes and resulting in me paying over 2 grand to get it repaired, They super seeded the oil pump they used to use with a new one and theirs many other reports online etc of the 2020 bmw m340 oil pump going out due to plastic internals which can lead to engine failure .
Too few reports in this category for a page of its own — they appear in the full complaint list.
Tires & wheels
Reports naming tires, wheels, hubs, or the tire-pressure monitoring system.
From owner reports, verbatim
I have owned my 2020 BMW m340iX for 2 years. During that time I have had 5 tires blow out, including 3 in the past 3 months alone. The tires are "run flat" and need to be completely replaced if they develop any issues. The dealer I use for service, who is owned by the manufacturer, says it is simply wear and tear - but this pattern is concerning and a potential safety issue for the car and tires.
TL* THE CONTACT OWNS A 2020 BMW M340I, EQUIPPED WITH PIRELLI TIRES, TIRE LINE: P7 CINTURATO, TIRE SIZE 225/40/R19, DOT NUMBER: NOT AVAILABLE. THE CONTACT STATED THAT WHILE THE VEHICLE WAS AT AN INDEPENDENT MECHANIC FOR SUSPENSION INSPECTION, THE MECHANIC BECAME AWARE OF BUBBLES IN THE DRIVER'S AND PASSENGER'S SIDE FRONT TIRES. THE PASSENGER FRONT TIRE ALSO EXHIBITED A SPLIT. THE TIRES WERE NOT REPLACED. THE MANUFACTURER WAS CONTACTED AND INFORMED OF THE FAILURE. THE APPROXIMATE FAILURE MILEAGE WAS 15,000.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Brakes
Reports naming service brakes, the antilock braking system, brake hoses, master cylinders or the parking brake.
From owner reports, verbatim
Electronic parking brake malfunction, disengage ineffective. Ongoing 2020 BMW mechanical issue, multiple dealer submissions, BMW refuses to open active recall. BMW requires $3,000 center panel replacement, out-of-pocket.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Other / unspecified
Reports whose component NHTSA recorded as unknown, or that do not map to one of the categories above.
From owner reports, verbatim
Component: Front differential / xDrive drivetrain system. Vehicle is available for inspection upon request. Description: My 2020 BMW M340i xDrive has exhibited a persistent whining noise from the front drivetrain since approximately 38,000 miles. The noise varies with speed and load and appears to originate from the front differential. A BMW dealership inspected the vehicle and acknowledged the noise but declined repair under warranty. This condition is consistent with premature wear of internal differential components such as gears or bearings, or improper lubrication. Differentials should not produce whining noises at this mileage, indicating a potential defect. Safety Risk: The front differential is critical to torque distribution in the all wheel drive system. Progressive failure could result in drivetrain binding, uneven torque delivery, or loss of AWD functionality. In a worst case scenario, partial or full differential seizure could occur, leading to sudden resistance, instability, or loss of control. These risks are heightened at highway speeds or in low traction conditions such as rain or snow. The vehicle provides no warning lights or messages despite the abnormal condition, meaning failure could occur without advance notice. Inspection: Issue confirmed by BMW dealership. No repair or corrective action performed. Warnings/Symptoms: No warning lights or system messages. Only symptom is a persistent whining noise from the front drivetrain. Additional Information: I am aware of similar complaints from other BMW xDrive owners reporting drivetrain whining, grinding, and vibration, suggesting a broader pattern of premature differential wear.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Elsewhere on this vehicle
Data sources
- NHTSA Office of Defects Investigation — owner-reported complaints and the components recorded on them
Data on this page last refreshed .