Attention! At the TDC position at the end of the compression stroke, the camshaft of the intake valves of cylinders 1–4 has play (Fig. 4.94) in the gear engagement of the actuator unit. This is normal.
During the work, do not allow the engine shaft to turn in the opposite direction (counterclockwise).
Removing the engine timing chain requires qualified specialists and special equipment and should only be carried out at CTOA-BMW, as it requires installation and adjustment of the valve timing.
[This publication was borrowed from an online resource «www.bmwman.ru»]