Oil Pump: Notes

The oil pump is mounted at an angle to the crankshaft bearing cap and is driven by the crankshaft using a roller chain. The oil pump is a two-stage gear oil pump with two parallel switched gear clusters.

Fig 1: Identifying Oil Pump Components

Courtesy of BMW OF NORTH AMERICA, INC.

The two pair of gear clusters are stacked one behind the other and work in two stages.

Stage two (both pump supply circuits) is only active in the lower engine speed range up to approx. 2,000 RPM to provide sufficient oil pressure for the VANOS at high oil temperatures.

Stage two is deactivated hydraulically at a pressure of 2 bar.

Fig 2: Identifying Pair Of Gear Clusters

Courtesy of BMW OF NORTH AMERICA, INC.