2019 BMW M340i Problems: 11 Known Issues

On the 2019-2020 BMW M340i B58B30 (B58TU), the second-generation B58 (B58TU) fitted to 2019-2020 M340i uses a variable-displacement oil pump whose pressure-regulating adjuster was made of thermoplastic. On cars built up to roughly mid-2020 the plastic component can crack, producing incorrect (high or low) oil pressure, a whine that follows engine RPM once warm, oil-level measurement that will not complete, and in the worst case a red oil-pressure warning. Owners on Bimmerpost report failures around 40,000-60,000 miles and have organized a petition for a recall. BMW's related software recall 21V-598 (already documented separately for brake assist) reflashed the DME to stop the crank from briefly rotating backwards at start, which was damaging the integrated oil/vacuum pump; the hardware fix is the later all-metal pump (part 11419895359) that replaced the plastic design from mid-2020 production. Do not confuse with the first-generation B58 in the F30 340i.

On the 2019-2025 BMW M340i B58, the rubber valve-cover gasket and the oil filter housing gasket on the B58 inline-six harden and crack from repeated heat cycling, allowing engine oil to seep out. It typically appears from roughly 60,000-100,000 miles. Leaking oil can drip onto hot exhaust components (burning smell) and pool in the spark-plug wells, eventually fouling coils/plugs and causing misfires if left unaddressed.

On the 2019-2022 BMW M340i, bMW SIB 65 23 23 and NHTSA campaign 23V-584 cover certain model-year 2019-2022 G20 M340i vehicles. Receiver Audio Module software may delay or fail to generate the audible driver seat-belt warning, causing noncompliance with FMVSS 208 and increasing injury risk if a driver relies on the reminder. Applicability is VIN-specific.

On the 2019-2022 BMW M340i, two software recalls hit the G20 M340i's rear-view camera under FMVSS 111. 19V-684 (Sept 2019, 257,473 BMW/Supra vehicles incl. 2019-2020 M340i) let the driver adjust the camera/display settings so that the rear image was no longer shown, and the car remembered the setting. 21V-096 (Feb 2021, 13,858 vehicles incl. 2019-2021 M340i/M340i xDrive) covered a fault where a portion of the rear image is obscured or the screen fails to illuminate when Reverse is selected. A third campaign in the same family, 22V-747 (Oct 2022), covers the 2023 330e only and does NOT list the M340i. Owners on Bimmerpost also report the iDrive 7 display going black for several seconds or the camera view failing to appear, which BMW treats with a PuMA software update.

On the 2019-2020 BMW M340i, on early G20 M340i and M340i xDrive sedans (plus early Z4, X3M/X4M, and three 2020 Toyota Supras), the steering-gear tie rods could be damaged under a combination of high ambient temperature and rough road surfaces, and a damaged rod could fracture, causing loss of steering control. BMW filed NHTSA recall 20V-355 in June 2020 covering 2,779 US vehicles (about 3,800 including Canada) and issued dealer procedure SIB 32 01 20. This recall is specific to early-production cars and is distinct from the later 2024 steering-gear recall and from the tie-rod-end noise bulletin.

On the 2019-2023 BMW M340i, separate from the fracture recall, a large number of G20 M340i owners report a knocking, cracking, or creaking noise from the front axle at low speed over bumps and expansion joints, often felt through the steering wheel and worse in warm weather. Dealers commonly replace lower control arms, sway-bar links, dampers and strut top mounts before finding the cause. BMW's SIB 32 01 23 ('Cracking/creaking noise from front axle/steering system') attributes it to excessive breakaway torque in the tie-rod thrust bearing on cars with the ThyssenKrupp (TKPS) electric power steering gear, and calls for replacing one or both tie-rod assemblies (both on cars built to 04/2019). A subset of owners only got relief when the dealer replaced the electric steering gear itself.

On the 2019-2024 BMW M340i B58, m340i owners report the 12V AGM battery discharging or dying, sometimes on relatively young cars, often triggered by short-trip driving, parasitic drains from modules not entering sleep mode, or a failing Intelligent Battery Sensor (IBS). German owners on motor-talk specifically flag early failures of the OEM Sebang battery. After any DIY battery swap, failing to register the new battery to the power-management system leads to undercharging and repeat failures, and can leave a black iDrive screen plus multiple warning messages after a disconnect.

On the 2019-2023 BMW M340i, a very common G20 electrical fault: one or both exterior mirrors stop folding or unfolding, stop adjusting, or lose power entirely. BMW SIB 51 13 18 attributes it to faulty electronics inside the exterior mirror creating a short on the LIN bus, which can also discolor or crack the mirror glass; the fault is often intermittent and can cascade into the driver's door switch cluster so that window and trunk-release buttons also stop responding. BMW revised the module and later changed the repair procedure to replace only the failed module, but Bimmerpost owners report repeat failures of the replacement, with some cars on their second or third mirror. Owners outside the 4yr/50k warranty have had partial goodwill coverage approved through BMW regional service.

On the 2019-2025 BMW M340i B58, owners report harsh or jerky shifts from the ZF 8-speed automatic, most noticeable on the 1-2 and 2-3 changes at low speed before the drivetrain is warmed up, and aggravated by Sport mode in cold stop-and-go traffic. The ZF 8HP is sensitive to fluid condition; degraded or low fluid worsens shift quality, and in more severe cases the mechatronic valve body/control unit develops faults causing erratic shifting and transmission warning lights.

On the 2019-2025 BMW M340i, g20 sedans with the moonroof develop a rattle, ticking, or cracking noise from the roof over rough pavement and in heat, which many M340i owners describe as the single most annoying flaw in an otherwise quiet cabin. BMW addressed it with two G20 service bulletins: SIB 54 15 19 (groaning over rough roads or during body flex, treated by applying BMW Lubricant M to the glass panel perimeter seal) and SIB 54 16 19 (clicking from the roller sunshade, treated by greasing the sunshade guide rails with RHF 1 sunroof grease); some dealers remove the glass to clean and re-lubricate the seals and rails. Multiple owners report the fix lasting only a few months before the noise returns, making it a recurring maintenance item rather than a permanent repair; a minority needed rail or panel replacement.

On the 2019-2025 BMW M340i, the M340i's standard M Sport brakes (blue four-piston front calipers, semi-metallic pads) squeal loudly at low speed and light pedal pressure, especially in stop-and-go traffic and after the pads heat-cycle. It is one of the most repeated complaints on G20 forums and continues from the F30 340i with the same caliper family. BMW's position is that it is a characteristic of the performance pad compound; the dealer measure (PuMA 52226124-01) removes all four sets of pads, deburrs the pad edges on the disc-bearing surface, cleans and lubricates the contact points and reinstalls them. Owners report the fix is temporary and the squeal returns within weeks to months; a change to a quieter aftermarket pad compound is the only lasting cure, at some cost to bite and fade resistance.