Spark plugs

The engine features a Bosch spark plug. The spark plug performs the task of introducing the ignition energy into the combustion chamber. Electrical sparking between the electrodes initiates combustion of the fuel-air mixture.

Spark plugs in jet-guided direct injection diesel engines are subject to specific requirements. A distinctive charge movement occurs in jet-guided direct injection diesel engines when compared to engines with intake pipe fuel injection. Geometrically, the spark plug must lie directly in the fuel injection trajectory. To do this, a precise torque of 23 Nm (+/- 3 Nm) must be observed during installation.

As the spark plug electrode is positioned particularly deep inside the combustion chamber. lean fuel-air mixture can also be ignited. This is important in the cold-start phase and in the so-called catalytic converter warm up phase. Multiple sparks are also discharged during this phase when, in contrast to previous Digital Motor Electronics (DME), all ignition-related diagnosis processes remain active.

Fig 1: Identifying Spark Plugs

Courtesy of BMW OF NORTH AMERICA, INC.