Oil Check Valves: Notes

Three oil check valves are inserted into each cylinder head from the outside. This prevents the engine oil from draining out of the cylinder head and the VANOS units.

The check valves are accessible from the outside, therefore; cylinder head removal is not necessary when changing the check valves  .

Fig 1: Identifying Oil Check Valves

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 2: Identifying Oil Check Valves In Different Design

Courtesy of BMW OF NORTH AMERICA, INC.