Check wastegate valve with vacuum
WARNING: This page does not describe the selected car, but rather 15 other vehicles, including the 2015 BMW Alpina B7L, 2015 BMW Alpina B7, 2014 BMW Alpina B7L, 2014 BMW Alpina B7, and 2013 BMW Alpina. However, it is still accessible from the selected car via links, so may be relevant.
Wastegate valves must be opened without vacuum.
The wastegate valves must close if a vacuum pressure is applied at the wastegate sockets (see BMW diagnosis system).
Check shaft on turbine wheel for rotatability.
Follow diagnosis instructions.