2020 BMW M340I engine problems

Updated from NHTSA data · How we count

42 owners have reported engine problems with the 2020 BMW M340I, 79% of all complaints about this model year. The typical problem appeared around 52,758 mi.

Engine complaints
42
Crashes
0
Fires
0
Injuries
0
Related recalls
2
Median mileage
52,758 mi

Specific components reported

Engine covers: stalling, loss of power, oil consumption, overheating.

ComponentComplaints
Engine38
Engine and engine cooling3
Engine and engine cooling:exhaust system:emission control:crankcase (pcv)1

Engine complaints across BMW M340I years

422020720211202212023
Engine complaints by model year. The 2020 is highlighted.

Mileage when the problem appeared

Under 10k110k–30k230k–60k160k–100k100k–150k150k+
Complaints that list mileage, grouped by odometer reading.

Related recalls

  • Recall 24V576000Aug 1, 2024105,588 vehicles
    ELECTRICAL SYSTEM:STARTER ASSEMBLY · ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM):SOFTWARE

    BMW of North America, LLC is recalling certain 2019-2020 X5, X7, 2020 3 Series Sedan, X6, 2020-2021 7 Series Sedan, 2020 8 Series Convertible, 8 Series Coupe, and 2020 8 Series Gran Coupe vehicles. Please see the recall report for the complete list of models. In the event the starter motor fails, repeated attempts to start the vehicle can cause the starter motor to overheat from an electrical overload.

    Risk: A starter motor that overheats can ignite nearby combustible material in the engine compartment, increasing the risk of a fire.

    Remedy: Dealers will update the vehicle software, free of charge. Owner notification letters were mailed September 27, 2024. Owners may contact BMW customer service at 1-800-525-7417.

  • Recall 21V598000Aug 2, 202150,024 vehicles
    ENGINE

    BMW of North America, LLC (BMW) is recalling certain 2020 M340i, M340i xDrive, 540i, 540i xDrive, X3 M40i, 2020-2021 X4 M40i, 745Le xDrive, 2019-2021 Z4 M40i, and 2020-2021 Toyota Supra vehicles. During engine start, the engine management software may cause loss of braking assist. Full mechanical braking (without assist) remains available.

    Risk: Loss of braking assist can increase the risk of a crash.

    Remedy: Dealers will update the engine management software, free of charge. Owner notification letters were mailed on September 17, 2021. Owners may contact BMW customer service at 1-800-525-7417.

What owners say

  1. Filed Sep 13, 2026CAEngine
    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…
    NHTSA complaint #11763922 · source
  2. Filed Sep 1, 2026NYEngine
    Oil pump for the 2020 model is made with plastic internals. The passage that controls the flow of oil into your engine is made of plastic. The car didn’t even have 40,000 miles and the plastic broke causing the passage to be in a very close to shut position not allowing enough oil to enter the engine in higher rpm. The mechanic told me this is the biggest thing he is starting to see and he works for BMW Service center of Mamaroneck. He’s seen over 150+ B58TU (engine model)…
    NHTSA complaint #11761189 · source
  3. Filed Aug 13, 2026OHEngine
    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…
    NHTSA complaint #11756783 · source
  4. Filed Jul 31, 2026TXEngine
    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…
    NHTSA complaint #11754090 · source
  5. Filed Jul 14, 2026LAEngine
    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…
    NHTSA complaint #11750244 · source
  6. Filed Jul 6, 2026AZEngine
    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…
    NHTSA complaint #11748524 · source
  7. Filed May 12, 2026CAEngine
    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.…
    NHTSA complaint #11737366 · source
  8. Filed Apr 10, 2026CAEngine
    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…
    NHTSA complaint #11730475 · source
  9. Filed Mar 27, 2026CAEngine
    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…
    NHTSA complaint #11727385 · source
  10. Filed Mar 23, 2026NYEngine
    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.…
    NHTSA complaint #11726317 · source
  11. Filed Mar 18, 2026NYEngine
    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…
    NHTSA complaint #11725310 · source
  12. Filed Mar 17, 2026TNEngine
    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 · source

Other 2020 BMW M340I problem areas

  • Other / Unknown (9)
  • Electrical System (6)
  • Wheels & Tires (3)
  • Fuel, Hybrid & EV Propulsion (3)
  • Transmission & Drivetrain (2)
  • Brakes (1)

Back to all 2020 BMW M340I problems →

Source: U.S. National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation public data. Complaints are submitted by owners and are not verified by NHTSA or by us; a complaint does not prove a defect exists. View this vehicle on NHTSA.gov Methodology