?A software error may cause an unwanted pressure pulsation in the transmission during a "Remote Engine Start."
full bulletin at NHTSA ↗2020 BMW M340i engine problems
moderate 28 complaints filed with NHTSA · avg repair $3,100 · see engine across all vehicles →
Complaints
28
Recalls
0
Avg fix
$3,100
When does it fail?
Of the 28 engine complaints filed for the 2020 BMW M340i, here's the actual mileage breakdown — failures cluster heaviest at 50,000-75,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Owners have filed 28 engine complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
In hot ambient conditions, if the engine was running for a prolonged time while the vehicle is stationary, a jolt may be experienced while lightly accelerating.
full bulletin at NHTSA ↗There is a howling or whistling noise from under the vehicle at 30 -37 mph (50 -60 km/h) when driving after a cold start, when the outside temperature is 32 F (0 C) or lower.
full bulletin at NHTSA ↗There is a howling or whistling noise from under the vehicle at 30 -37 mph (50 -60 km/h) when driving after a cold start, when the outside temperature is 32 F (0 C) or lower. The noise goes away as the vehicle/driveline reaches operating temperature.
full bulletin at NHTSA ↗There is a howling or whistling noise from under the vehicle at 30 -37 mph (50 -60 km/h) when driving after a cold start, when the outside temperature is 32F (0C) or lower.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The 2020 BMW M340i equipped with the B58TU engine has a critical oil pump defect. The pump contains an internal thermoplastic adjusting ring that fractures from repeated heat and cold cycling, causing sudden loss of oil pressure. Owners cannot rely on electronic oil level readings—the display typically fails to read above 18–21%—and the vehicle has no physical dipstick as backup.
Failures begin as early as 5,000 miles and escalate without clear warning. Owners report the engine stalls during highway driving or fails to start after cold starts. When the pump fails, symptoms include thick white exhaust smoke, loud engine noise, and metal debris visible inside the engine. One owner's engine developed a sizable hole in the block.
The fix is expensive: $2,500–$8,000 to replace the pump, which requires extensive disassembly. BMW switched to an all-metal pump design in 2021 model year vehicles but has not issued a full recall for 2019–2020 models. One owner's vehicle failed again after NHTSA Campaign 24V576000 recall service. BMW reportedly removed the plastic part number from dealer systems, making it unclear which vehicles still have the defective pump installed.
Failure modes owners describe
Oil Pump Thermoplastic Component Fracture
The B58TU engine's variable-displacement oil pump contains an internal thermoplastic adjusting ring or component that fractures due to repeated thermal cycling (heating and cooling). This failure causes sudden loss or erratic regulation of engine oil pressure, potentially leading to catastrophic engine damage from oil starvation.
When: Cold-start operation in low ambient temperatures; failures reported as early as 5,000–20,000 miles, with some occurring at 28,162, 46,500, 55,000, 59,015, and 82,500 miles
Symptoms owners cite: Loss of electronic oil level reading (fails to display above 18–21%); Abnormal oil pressure behavior (erratic or unstable readings); Sudden low oil pressure warnings; Thick white smoke from exhaust pipes; Abnormal ticking or loud banging sounds from engine; Engine hesitation or failure to start; Engine stall during highway driving or acceleration; Metal debris visible after pump failure
Repairs/costs cited: Oil pump replacement costs range $2,500–$8,000 depending on labor and whether engine damage has occurred. Replacement part uses metal internals instead of thermoplastic. Repairs require extensive engine disassembly.
Recalls/TSBs owners mention: NHTSA Campaign 24V576000 (Electrical System, Engine and Engine Cooling) was issued; however, at least one owner reported the recall repair failed and the failure reoccurred. BMW updated the design to metal components in 2021 and newer model years but has not issued a blanket recall for 2019–2020 vehicles. BMW reportedly removed the plastic part number from dealer networks and VIN-based parts information.
Oil Level Sensor Malfunction
The electronic oil level measurement system in the instrument cluster fails to display oil level accurately. The sensor stops reading above a certain threshold (typically 18–21%), preventing owners from gauging actual oil quantity. This often precedes or accompanies oil pump failure.
When: Reported across various mileages; one case at approximately 46,500 miles
Symptoms owners cite: Electronic oil level display frozen at 18–21% and will not increase; Unable to measure oil electronically with no physical dipstick as backup; Measurement failure prior to or concurrent with oil pump fracture
Repairs/costs cited: Typically resolved by replacement of the oil pump assembly, though some owners report uncertainty whether oil pump replacement alone solves the issue. Repair cost $2,500–$6,000+.
Recalls/TSBs owners mention: Dealers acknowledge the issue is tied to oil pump failure; some report BMW NA directed them to remove and inspect the oil pump.
Engine Seizing and Catastrophic Damage
When oil pump failure results in sustained loss of oil pressure, insufficient lubrication of critical engine components (cam plate, bearing surfaces) causes rapid mechanical wear and engine seizure. One owner reported a sizable hole in the engine block and visible metal damage to the cam plate and oil pump area.
When: Can occur suddenly during or shortly after vehicle operation once oil pump has failed; one case noted at 59,015 miles
Symptoms owners cite: Sizable hole in engine block; Metal debris visible inside engine; Loss of engine propulsion without warning; Metal filings or shavings found upon inspection; Potential for engine to seize if pump failure is not immediately halted
Repairs/costs cited: Catastrophic damage may render engine unrepairable; costs for engine replacement not detailed in narratives. One owner reported metal falling out of engine with visible damage to cam plate.
Drivetrain Malfunction Warnings and Engine Stall
Owners report sudden warning messages indicating low oil pressure and urgent shutdown commands appearing while driving. In severe cases, the engine stalls without prior illuminated warning lights, creating an immediate hazard in traffic conditions.
When: Reported during highway driving and acceleration; no specific mileages provided for this failure mode alone
Symptoms owners cite: Sudden 'low oil pressure' warning message; Drivetrain malfunction warning light; Engine stall during highway driving or acceleration; No illuminated warning lights prior to stall in some cases; Vehicle loss of power steering assist following engine loss; Inability to restart or multiple failed start attempts
Synthesized from 28 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 8 most recent
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…
Unable to read oil measurements Above 18% many 2020’s have a had a oil pump replacement
Oil level won’t read. Can cause engine issues. Car has no dipstick to check for oil
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…
Oil doesn’t read correctly Might be issue with oil pump
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…
Oil measurement fails at 20%, unable to tell how much oil is in engine, can lead to severe engine damage where the engine seizes and you loose power brakes and steering. Dealer says only fix is oil pump replacement.
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…
Had engine trouble with your 2020 BMW M340i?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2020 BMW M340i?
It's a documented issue but not catastrophic. 28 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Based on the 28 complaints filed, engine issues most often appear around 54,044 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2020/BMW/M340i.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.