NHTSA complaint #11709973

Owner complaint summary

What component or system failed or malfunctioned, and is it available for inspection upon request? The variable displacement oil pump contains a plastic (Duoplex) internal adjusting ring/vane carrier that is known to become brittle and shatter. Status: While the pump has not yet suffered a total mechanical collapse, it is a documented inherent defect. The manufacturer (BMW) has already superseded this part (Original #11418646454 or ...453) with a reinforced metal version (Part #11419895359), admitting the original material was insufficient for the engine's lifespan. How was your safety or the safety of others put at risk? Risk: The failure mode is sudden and unpredictable. If the plastic ring shatters while driving, it can lead to an instantaneous loss of oil pressure, causing the engine to seize or stall at highway speeds. This creates an immediate risk of: Loss of power steering and braking assist in traffic. Potential rear-wheel lockup (in RWD/Manual configurations) leading to loss of vehicle control. Catastrophic engine failure in the middle of active traffic, requiring an emergency maneuver. Has the problem been reproduced or confirmed by a dealer or independent service center? Assessment: The existence of the defect is confirmed by BMW’s internal technical case PuMA Measure 65494813. Furthermore, the manufacturer released a software update (S18A-21-03-567) specifically to reduce oil pressure during cold starts to mitigate stress on this plastic component—a "band-aid" fix that acknowledges the hardware's fragility. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Assessment: Not yet, as the vehicle is being operated under the assumption of a known safety defect. However, independent mechanics and BMW master technicians across the industry have verified that early B58TU builds (2018–2020) almost universally contain the defective plastic-internals pump.