BMW M340I engine failure problems

Filed Jul 31, 2026 · Engine · TX

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.

Filed Jul 14, 2026 · Engine · LA

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.

Filed Jul 6, 2026 · Engine · AZ

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.

Filed May 12, 2026 · Engine · CA

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.

Filed Apr 10, 2026 · Engine · CA

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.

Filed Mar 23, 2026 · Engine · NY

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.

Filed Nov 3, 2025 · Engine, Transmission · MA

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 .

Filed Sep 23, 2025 · Engine · TX

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 the federal safety agency, 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.

Filed Apr 18, 2025 · Engine · NY

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.

Filed Mar 4, 2025 · Engine · WA

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.