Turbocharger - Diesel: Description

The turbocharger used on BMW diesel engines is designed for efficiency and performance. The turbocharger consist of a turbine/compressor assembly, oil supply system and wastegate. The turbine driven wheel compresses air and forces it into the engine. This extra air being supplied to the engine is called "boost".

The amount of boost is controlled by the wastegate and diaphragm. The diaphragm is exposed to turbocharged boost. As boost increases, The diaphragm pushes against the wastegate actuator rod. Actuator rod opens the wastegate to limit amount of boost by diverting exhaust gases away from the turbine.