VANOS is mounted to V8 engine cylinder heads, and some specific tools and processes are required for removing the VANOS units when the cylinder heads are removed. Generally, one should be aware of the whole process before proceeding to the repair task. This can be done without special equipment, and if done loose valves can bend from contacting the piston crown and camshafts can bend if overstressed as when removing or assembling. As for VANOS - the acronym derived from VAriable NOckenwellen Steuerung, which is German - stands for variable camshaft timing. The disassembly process for VANOS is described under camshaft and camshaft timing in this page. There is separate information on the removal and installation procedures of the right and left cylinder heads; also, the intake manifold must be unbolted before the removal of either cylinder head. If for some reasons a cylinder head needs extensive reconditioning after removal from an engine, a remanufactured cylinder head is available from the BMW authorised source.