NHTSA complaint #11763291

Owner complaint summary

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 engine oil pressure. Failures have been reported in which this internal plastic component fractures, resulting in sudden loss of or instability in engine oil pressure. My own vehicle has experienced this oil pump failure. The failure is particularly concerning because it can occur during cold-start operation and appears to be more prevalent in low ambient temperatures. When the internal component fails, oil pressure regulation can become erratic or be lost entirely. The resulting loss of lubrication can lead to severe engine damage or vehicle disablement. Reported precursor symptoms include an inability to electronically measure the engine oil level, abnormal oil-pressure behavior, drivetrain malfunction warnings, and other warning messages. However, these symptoms may provide little meaningful advance warning before the vehicle becomes disabled or the engine sustains significant damage. The safety concern is not limited to the cost of the repair. A sudden loss of oil pressure can cause the vehicle to become disabled without warning while driving or shortly after startup. This presents a potential safety hazard if the vehicle loses power or becomes immobilized in active traffic. The risk is particularly concerning during cold-weather operation, when these failures appear to occur most frequently. In winter conditions, occupants of a disabled vehicle may also be exposed to freezing temperatures while waiting for roadside assistance. Replacement of the oil pump is a major repair with cost ranging $6000-8000, even when engine has not been damaged. These costs are secondary to the safety concern but demonstrate the seriousness of the defect and the potential severity.