2020 Bmw M340i Complaints

  • Engine 02/10/2026

    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...

  • Engine 05/14/2025

    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.

  • Engine 03/27/2026

    Oil pump failure

  • Engine 12/19/2025

    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.

  • Engine 03/18/2026

    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 caus...

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