2020 BMW M340I engine problems

ENGINE

I am reporting a premature oil pump failure on my 2020 BMW M340i xDrive with 42 thousand miles. The vehicle has been well maintained and has not experienced any oil pressure warning lights. However, the electronic engine oil level measurement repeatedly fails to complete once the engine is fully warmed up. I have also received stored BMW fault code 21B2C7 relating to engine oil pressure plausibility/excessive oil pressure. The fault currently shows as inactive, but it was not present previously. I have monitored engine oil pressure using diagnostic software. Pressure is generally around 38–42 psi at hot idle, approximately 44–48 psi during cruising, and can rise into the 60–78 psi range during acceleration. Although these readings are generally stable, the combination of the stored pressure plausibility fault and repeated inability to measure the engine oil level is concerning. I have also noticed a whining/humming noise from the front of the engine at low RPM, particularly during stop-and-go driving and while decelerating in first and second gear. There are numerous owner reports involving premature oil pump failures on BMW vehicles equipped with this generation of the B58 engine. The original oil pump used on earlier vehicles reportedly contains plastic internal components that can deteriorate over time and heat exposure. BMW later revised the oil pump design. BMW Korea has also reportedly begun providing repairs for certain B58 oil pump failures outside the normal warranty period while the issue is being investigated in that market. An engine oil pump is a critical lubrication component and is not a normal maintenance or wear item. Failure of the pump could result in insufficient or excessive oil pressure, loss of lubrication, severe engine damage, engine seizure, or loss of power while driving. I am submitting this complaint so NHTSA is aware of the potential pattern of premature oil pump failures affecting 2020 BMW M340i vehicles and

NHTSA complaint #11756783 — an unverified report by a vehicle owner.

ENGINE

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.

NHTSA complaint #11754090 — an unverified report by a vehicle owner.

ENGINE

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.

NHTSA complaint #11750244 — an unverified report by a vehicle owner.

ENGINE

I am submitting this complaint regarding a potential safety defect involving the engine lubrication system on my 2020 BMW M340i with the B58 engine. The vehicle was purchased used from a single owner with low mileage and comprehensive maintenance records, with no indication of prior engine or lubrication issues. While traveling at highway speed, the vehicle suddenly displayed a low oil pressure warning and simultaneously entered a protective shutdown strategy, resulting in a significant loss of engine power. This forced me to rapidly slow down and merge across multiple lanes of traffic to reach the shoulder, creating a dangerous situation with a substantial risk of a rear-end or multi-vehicle collision. There were no warning lights, fault messages, drivability concerns, or other symptoms before this incident. According to the authorized BMW dealership that inspected the vehicle, the engine experienced an oil pump failure that caused a loss of oil pressure, resulting in internal engine damage. The dealership found metal shavings in the engine oil and recommended complete engine replacement rather than repairing the oil pump due to the extent of the damage. The vehicle and failed components are available for inspection upon request. Based on the dealership's diagnostic findings, there were no stored oil pressure fault codes prior to the failure; the only oil pressure warning occurred at the time the engine lost power. I am concerned that this indicates the vehicle did not provide meaningful advance warning before a catastrophic failure occurred. I believe this may represent a defect in the oil pump assembly that warrants investigation. I have seen many reports from other owners discussing failures involving the B58 oil pump assembly, including concerns about an internal plastic component that many owners proactively replace with an aftermarket metal component to reduce the risk of failure. This failure posed an incredible safety risk to me and others on the road.

NHTSA complaint #11748524 — an unverified report by a vehicle owner.

ENGINE

Engine oil pump is failing. Early production 2019-2020 model years are made of plastic which can crack and break resulting in engine failure while driving. This is a well documented issue regarding the BMW B58 Engine (2nd Generation) They have since updated the engine oil pump part to a durable metal pump on newer models leaving the older ones with the bad part with no resolution. The vehicle no longer measures the oil level and is a symptom of the pump starting to fail. There is no telling when it may go out and it will be too late at that point as it results in complete engine failure/seizure while driving without proper pressure and lubrication. The local BMW Dealer says they are unable to help as BMW does not have a recall or technical service bulletin addressing this issue leaving owners with this plastic oil pump to pay out of pocket when this part fails destroying the motor. This is a critical safety hazard as the motor may shut off or malfunction at any given time while driving. The vehicle may produce a warning light or malfunction codes via the OBD, but at that point may be too late as the damage has already occurred. My independent bmw mechanic has also stated he sees many cars within this model year timeframe facing this issue as they age outside of the warranty period quoting $5K+ to ensure safety and fix this issue properly with the updated metal part. This is ridiculous as these cars by now are outside of the factory warranty period of 4 years and 50,000 miles. My vehicle does not measure the oil anymore even after a oil change leaving a big question mark of whether there is the proper amount of oil to lubricate the engine or not. I have attached pictures of the plastic oil pump showing cracks and breaks as well as the updated fully metal oil pump. There is no peace of mind when driving this vehicle due to this issue.

NHTSA complaint #11737366 — an unverified report by a vehicle owner.

ENGINE

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) 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. Increasing wear on internal engine components and even leading to irreversible engine damage. 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. BMW is aware of this defect as they chose to update the design in future models, switching from the brittle plastic to more metal components in the updated design. This shows clearly that this design is compromised and was a risk to continue implementing.

NHTSA complaint #11730475 — an unverified report by a vehicle owner.

ENGINE

I’ve been doing research for this particular issue on the 2020 bmw m340i (B58 engine). There is a plastic housing on the oil pump that seems to completely collapse due to consistent heat cycles (starting the vehicle). As far as I know that common symptoms include not being able to read oil levels and this is what commonly shows a faulty or unreliable oil pump that could potential cause a oil leak into engine where it gets hot and cause a fire. This is extremely dangerous and only the vehicles made from 2019-2020 have this plastic part that should be recalled from factory.

NHTSA complaint #11727385 — an unverified report by a vehicle owner.

ENGINE

Oil pump failure

NHTSA complaint #11727567 — an unverified report by a vehicle owner.

ENGINE

Engine failed suddenly while driving on a highway. While driving at highway speed, warning lights and messages appeared indicating oil pressure is low and to turn off the engine immediately. The vehicle was towed to the shop where it was discovered that the oil pump, which was made out of plastic, had suffered a catastrophic failure. Was told if the engine continued running any longer it would have seized which could pose a very serious safety issue when at highway speeds. The vehicle had 55,000 miles at time of failure. Repairs totaled nearly $6,000 including towing and rental with a month of lost vehicle use. The failed oil pump was retained.

NHTSA complaint #11726317 — an unverified report by a vehicle owner.

ENGINE

I am reporting a safety concern involving BMW vehicles equipped with the B58 Technical Update (B58TU) engine, commonly found in model years 2019–2021. These vehicles utilize a variable-displacement engine oil pump containing an internal thermoplastic adjusting component responsible for regulating oil pressure. Field failures are increasingly being reported in which this internal component fractures, resulting in sudden loss or instability of engine oil pressure. The failure frequently occurs during cold-start operation in low ambient temperatures. When the component fails, oil pressure regulation becomes erratic or is lost entirely. In many cases, drivers receive little or no actionable warning prior to engine damage or vehicle disablement. Reported precursor symptoms include inability to electronically measure engine oil level, abnormal oil pressure behavior, or sudden drivetrain malfunction warnings. Failures may rapidly progress to engine shutdown or severe mechanical damage caused by oil starvation. Loss of lubrication can cause the vehicle to become disabled without warning while driving or shortly after startup. This creates a safety hazard, particularly when vehicles become immobilized in active traffic or during winter conditions the cold is when they fail the most, where occupants may be exposed to freezing temperatures while awaiting assistance. Replacement of the oil pump requires extensive disassembly of the vehicle and repairs commonly exceed $6,000–$8,000 for just the pump, assuming the motor is unharmed. Owners are currently unable to determine whether their vehicles contain the original thermoplastic oil pump design or a later revised version utilizing metal internal components, as VIN-based parts information now identifies updated components in the car even when no replacement has occurred and the old components are actually in the car. Also, BMW has actively removed the plastic part number out of all dealer networks as well.

NHTSA complaint #11725310 — an unverified report by a vehicle owner.

ENGINE

EXHIBITING SIGNS OF NOT BEING ABLE TO READ OIL LEVELS WHICH IS A POTENTIAL SIGN OF OIL PUMP FAILURE DUE TO PLASTIC INTERNAL COMPONENTS THAT HAS OCCURED IN 2020 MODELS.

NHTSA complaint #11724900 — an unverified report by a vehicle owner.

ENGINE

I am reporting a safety concern involving BMW vehicles equipped with the B58 Technical Update (B58TU) engine, commonly found in model years 2019–2021. These vehicles utilize a variable-displacement engine oil pump containing an internal thermoplastic adjusting component responsible for regulating oil pressure. Field failures are increasingly being reported in which this internal component fractures, resulting in sudden loss or instability of engine oil pressure. The failure frequently occurs during cold-start operation in low ambient temperatures. When the component fails, oil pressure regulation becomes erratic or is lost entirely. In many cases, drivers receive little or no actionable warning prior to engine damage or vehicle disablement. Reported precursor symptoms include inability to electronically measure engine oil level, abnormal oil pressure behavior, or sudden drivetrain malfunction warnings. Failures may rapidly progress to engine shutdown or severe mechanical damage caused by oil starvation. Loss of lubrication can cause the vehicle to become disabled without warning while driving or shortly after startup. This creates a safety hazard, particularly when vehicles become immobilized in active traffic or during winter conditions the cold is when they fail the most, where occupants may be exposed to freezing temperatures while awaiting assistance. Replacement of the oil pump requires extensive disassembly of the vehicle and repairs commonly exceed $6,000–$8,000 for just the pump, assuming the motor is unharmed. Owners are currently unable to determine whether their vehicles contain the original thermoplastic oil pump design or a later revised version utilizing metal internal components, as VIN-based parts information now identifies updated components in the car even when no replacement has occurred and the old components are actually in the car. Also, BMW has actively removed the plastic part number out of all dealer networks as well.

NHTSA complaint #11721301 — an unverified report by a vehicle owner.

ENGINE

Oil pump in B58 BMW engines 2019-2022 has been a major safety concern that results in catastrophic failure while driving the vehicle. All because of BMW using a plastic component and quietly changed it, meanwhile hundreds of people had a major oil leak and engine seizures on hwy and $5k+ repairs.

NHTSA complaint #11721135 — an unverified report by a vehicle owner.

ENGINE

Oil pump is made of plastic causing it to fail after a certain time and can lead to a total engine loss if not swapped out with BMW’s updated oil pump. They are aware of the issue but neglecting to handle the problem.

NHTSA complaint #11721171 — an unverified report by a vehicle owner.

ENGINE

Oil Pump Failed its common issue on them but no recall

NHTSA complaint #11721090 — an unverified report by a vehicle owner.

ENGINE

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.

NHTSA complaint #11718142 — an unverified report by a vehicle owner.

ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:CRANKCASE (PCV)

The contact owns a 2020 BMW M340I. The contact stated that after an oil change was performed by an independent mechanic, there was a large amount of gray smoke coming from the exhaust pipe while accelerating from a complete stop. There was no warning light illuminated during the failure. The vehicle was taken to various independent mechanics, and the failure was associated with the PCV (Positive Crankcase Ventilation) valve cover. The contact stated that there was a recall on other model vehicles for the failure; however, neither the VIN nor the model vehicle was included in the recall. The manufacturer was notified of the failure. The vehicle was not repaired. The failure mileage was approximately 46,500.

NHTSA complaint #11714559 — an unverified report by a vehicle owner.

ENGINE AND ENGINE COOLING

The contact owns a 2020 BMW M340I. The contact stated that upon starting the vehicle, the contact noticed a thick white smoke coming out of the exhaust pipes. In addition, the contact stated that there was an abnormal ticking sound coming from the engine while idling. There was no warning light illuminated. The vehicle had not yet been diagnosed or repaired. The manufacturer had yet to be notified of the failure. The failure mileage was approximately 82,500.

NHTSA complaint #11707622 — an unverified report by a vehicle owner.

ENGINE

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 .

NHTSA complaint #11697131 — an unverified report by a vehicle owner.

ENGINE

Oil pump common issue of made out plastic cause miss interpretation of oil pressure. Developing engine issues under 50k miles

NHTSA complaint #11690406 — an unverified report by a vehicle owner.

ENGINE

Hi. I’d like to point out I have not had an incident YET thankfully. However, I want to highlight that the early M340i production releases (2019 and 2020) are HIGHLY likely to experience catastrophic engine failure due to an oil pump being made of plastic on some models. Of the 20 or so complaints listed under this vehicle on NHTSA, I’ve already seen PLENTY of complaints regarding this issue and people actually experiencing this issue. I believe if a car has a fair chance of causing catastrophic damage to its engine on its own, it poses as a safety risk for anyone in or around the car. The fix is to spend $6000-$7000 to have the oil pump replaced with the new 2021 oil pump, but most normal people cannot afford that easily and are driving around with plastic pumps still hoping for the best. I don’t understand how so many complaints of the same safety issue on this website for this vehicle (and other vehicles, which have the same B58 engine) have not resulted in a recall. Hopefully this can change because a car destroying itself shouldn’t be taken lightly and I’d like to second what everyone else on here is saying about the oil pump issue.

NHTSA complaint #11689265 — an unverified report by a vehicle owner.

ENGINE AND ENGINE COOLING

The contact owns a 2020 BMW M340I. The contact stated that while merging onto the highway and accelerating, there was an abnormally loud banging sound coming from the vehicle before the vehicle stalled. The contact was able to coast forward. There were no warning lights illuminated. The contact removed the panels, and there was metal falling out. The contact stated that there was a sizable hole in the engine, and metal was showing from the cam plate and oil pump. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted regarding recalls and warranty coverage but it was recommended that the contact call the NHTSA Hotline for assistance. The approximate failure mileage was 59,015.

NHTSA complaint #11686855 — an unverified report by a vehicle owner.

ENGINE AND ENGINE COOLING

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.

NHTSA complaint #11659699 — an unverified report by a vehicle owner.

ENGINE

I cruised on a city street at the speed limit. The light turned red and I came to a full stop. The start/stop system was activated and the engine “stopped” to conserve power while my foot was on the brake. The light turned green and I took my foot off the brake, the engine failed to start and did not start with countless attempts. Digital cluster and CarPlay proceeded to work, exterior lights work. Called a tow to the nearest BMW dealership for assistance.

NHTSA complaint #11655346 — an unverified report by a vehicle owner.

ENGINE

Car will not measure oil past 20%. Seems like lots of 2020 models have a faulty production oil pump. Car is now out of warranty and dealer charged $5000 to fix the issue but do not know 100% if oil pump replacement will fix it. BMW changed the oil pump in the later models but did not mention anything about any recalls or replacements. Unacceptable.

NHTSA complaint #11652542 — an unverified report by a vehicle owner.

ENGINE

I am unable to read the oil level in my 2020 M340i. Upon checking the oil pressure, the oil pressure goes above 45psi which is the cutoff for the measurement check. Under heavy acceleration, the oil pressure will go over 90psi. My car needs the oil pump to be replaced. The plastic ring surrounding the oil pump for variable oil pressure will crack and lead to a high oil pressure scenario, eventually leading to catastrophic engine damage. BMW has refused to acknowledge this even though they installed an updated all-metal oil pump in 2021 and newer M340i.

NHTSA complaint #11648849 — an unverified report by a vehicle owner.

ENGINE

Oil pump manufacturing fault. One of the internal components on the oil pump for these B58 engines contains a ring that is made of plastic. Due to its the nature of this type of material, when it is heated and cooled, over time it becomes brittle and cracks. Damage to this internal component is leading to oil pump failure, and eventually engine failure. There is no recall on this yet, which is highly concerning. Basically my oil pump is a ticking time bomb waiting to fail, and BMW refuses to address the issue. Attached are photos of different oil pumps from the exact same engine as mine, containing the plastic ring which is visibly damaged from repeated exposure to hot and cold temperature fluctuations. Once this ring goes bad, engine damage may be catastrophic.

NHTSA complaint #11646288 — an unverified report by a vehicle owner.

ENGINE

The starter malfunctioned causing electrical damage to the motor and related components. Although there is literature that exists that this is a potential problem for this vehichle, BMW refuses to fix the problem and is asking me to pay. My warranty is expired by 4 months, but I have only 37,800 miles. The fact that there are 105K vehicles with this potential problem is evidence that this problem exists. They should be paying for what is an obvious manufacturer defect.

NHTSA complaint #11631042 — an unverified report by a vehicle owner.

ENGINE

Oil level won’t read. Can cause engine issues. Car has no dipstick to check for oil

NHTSA complaint #11616542 — an unverified report by a vehicle owner.

ENGINE

Oil doesn’t read correctly Might be issue with oil pump

NHTSA complaint #11611857 — an unverified report by a vehicle owner.