Slackening the hydraulic chain tensioner of cylinder bank 1

NOTE: RISK OF DAMAGE 
Damage to timing chain or timing chain drive  .
Turning the engine without chain tensioner or special tool can result in damage to the timing chain and timing chain drive  .

• Always turn the engine with the chain tensioner or the special tool.

• Position the special tool 0 491 012 (11 4 120) (3)  in the bore and fasten the chain tensioner piston.

Courtesy of BMW OF NORTH AMERICA, INC.