This bulletin applies to 2013 BMW vehicles equipped with the N54 turbocharged engine. A slight rattle noise may be heard from the engine compartment after turning the engine off. This noise is similar to a mechanical typewriter. In addition, a slight reduction of power, similar to a turbo lag, may be experienced.
The vacuum supply to the waste gates may be restricted or blocked. The EPDM vacuum supply hoses that connect the pressure converter or vacuum solenoid can kink if they are bent too sharply or not installed in the hose retaining clip properly.
Re-route the vacuum supply hose so that a kink or restriction no longer exists.