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2020 BMW M340I engine complaints

Page 2 of 3: complaints 11 to 40 of 46, newest first, as owners wrote them.

See the summary of 2020 BMW M340I engine problems: which part fails, at what mileage and related recalls.

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 27, 2026 · Engine · GA

Oil pump failure

Filed Mar 27, 2026 · Engine · CA

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.

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 Mar 18, 2026 · Engine · NY

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.

Filed Mar 17, 2026 · Engine · TN

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.

Filed Mar 1, 2026 · Engine · TX

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.

Filed Feb 28, 2026 · Engine · ND

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.

Filed Feb 28, 2026 · Engine · CA

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.

Filed Feb 27, 2026 · Engine · SC

Oil Pump Failed its common issue on them but no recall

Filed Feb 15, 2026 · Electrical, Engine · NY

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.

Filed Jan 30, 2026 · Engine · 46,500 miles · CA

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.

Filed Dec 29, 2025 · Engine · 82,500 miles · CA

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.

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 29, 2025 · Engine · CA

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

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 Sep 12, 2025 · Engine · 59,015 miles · PA

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 federal safety agency Hotline for assistance. The approximate failure mileage was 59,015.

Filed May 8, 2025 · Electrical, Engine · 28,162 miles · IL

The contact owns a 2020 BMW M340I. The contact stated that the vehicle was repaired under the federal safety agency 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 federal safety agency Hotline for assistance. The failure mileage was approximately 28,162.

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 Apr 3, 2025 · Engine · OH

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.

Filed Mar 17, 2025 · Engine · PA

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.

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.

Filed Dec 16, 2024 · Electrical, Engine · CA

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.

Filed Sep 26, 2024 · Engine · CT

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

Filed Aug 30, 2024 · Engine · CA

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

Filed Aug 21, 2024 · Electrical, Engine · CA

Brought my car in for a starter recall picked it up next day and drove home then came out to turn my vehicle on again and it wouldn’t start. Burning smell from engine bay as well. Returned the car they inspected it and told me a faulty starter. When I brought the car in it was in perfect working condition I only brought it for the recall. I was then held accountable for 25% of repair costs.

Filed Jul 25, 2024 · Engine · UT

Oil pump failure, causing inability to read oil level. Also flickering oil light on and off. After some research noticed it was happening to a lot of others as well due to oil pump being made with plastic internals. BMW has since updated to a new pump with metal internal the next year however never recalled old pumps.

Filed Mar 12, 2024 · Engine · CA

Car was driving fine after a dealer oil change, then on a long road trip I get the error message "low oil pressure" stop car and take back to a service center. BMW dealership in San Rafael CA says that BMW NA told them to remove the oil pump and inspect it, but that it may not solve the issue. My car has a [XXX] production date according to the VIN. There are many other BMW M340 owners that have had to get their oil pumps replaced for the 2020 model year, same as mine. The new oil pump has a different design, metal impeller vs. plastic on the old one. The repair cost is quoted by the dealer as $6k + the parts, and they still wont know if it fixes the issue. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Dec 13, 2023 · Engine · VA

Unable to read oil measurements Above 18% many 2020’s have a had a oil pump replacement

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