🟢 BMW E90 320d N47 swirl flap failure — inlet manifold

Engine management light, rough running, and reduced performance. The swirl flaps inside the inlet manifold of the N47 engine are plastic and break off, potentially entering the engine and causing catastrophic damage. Removing and blanking the swirl flap actuator shaft is the standard preventive repair carried out by most N47 specialists. The blanking procedure is well established and does not significantly affect everyday performance.