Remove both timing chains

Preliminary work 

• Refer to REMOVING THE RIGHT ENGINE MOUNTING BRACKET (PHEV) .
• Refer to INSTALLING THE ENGINE ON THE ASSEMBLY JIG .
• Refer to REMOVING BEARING BRACKET .
• Refer to REMOVING FRONT AXLE DIFFERENTIAL .
• Refer to REMOVING THE OIL FILLER CAP .
• Refer to RELEASING THE OIL DRAIN PLUG .
• Refer to TIGHTENING THE OIL DRAIN PLUG .
• Refer to REMOVING AUXILIARY COOLANT PUMP FOR THE EXHAUST TURBOCHARGER .
• Refer to REMOVING THE COOLANT RETURNING LINE FOR THE EXHAUST TURBOCHARGER (AUXILIARY COOLANT PUMP REMOVED) .
• Refer to REMOVING THE COOLANT FEED LINE FOR THE EXHAUST TURBOCHARGER (COOLANT RETURNING LINE REMOVED) .
• Refer to REMOVING FRONT ENGINE ENCAPSULATION .
• Refer to REMOVING THE OIL FEED LINE FOR THE EXHAUST TURBOCHARGER (ENGINE ENCAPSULATION REMOVED) .
• Refer to REMOVING TANK VENT VALVE .
• Refer to REMOVING INTAKE PLENUM .
• Refer to REMOVING IGNITION COILS .
• Refer to REMOVING THE HIGH PRESSURE LINE BETWEEN THE HIGH PRESSURE PUMP AND THE RAIL .
• Refer to REMOVING THE INJECTORS .
• Refer to REMOVING HIGH PRESSURE PUMP .
• Refer to REMOVING BOTH ACTUATORS (ENGINE REMOVED) .
• Refer to REMOVING THE CYLINDER HEAD COVER (ENGINE REMOVED) .
• Refer to REMOVING THE ACOUSTIC COVER OF THE OIL SUMP .
• Refer to REMOVING THE THERMOSTAT FROM THE TRANSMISSION OIL LINES .
• Refer to REMOVING THE STARTER MOTOR (ACOUSTIC COVER REMOVED) .
• Refer to TURNING THE ENGINE ON THE VIBRATION DAMPER .
• Refer to BLOCKING THE CRANKSHAFT IN HE TDC FIRING POSITION OF CYLINDER 1 .
• Refer to BLOCKING THE CAMSHAFTS .
• Refer to REMOVING THE CHAIN TENSIONER (ENGINE REMOVED) .
• Refer to RELEASING THE VANOS CENTRAL VALVE .
• Refer to REMOVING EXHAUST CAMSHAFT ADJUSTER .
• Refer to REMOVING INTAKE ADJUSTER .
• Refer to DISASSEMBLING ALL SPECIAL TOOLS .
• Refer to REMOVING THE OIL RETURN LINE FOR THE EXHAUST TURBOCHARGER .
• Refer to REMOVING THE CYLINDER HEAD .
• Refer to REMOVING FLYWHEEL .
• Refer to REMOVING OIL SUMP .
• Refer to REMOVING REAR TIMING CASE COVER .
• Refer to REMOVING THE OIL VACUUM PUMP .

• Remove the drive chain (1)  .

  Courtesy of BMW OF NORTH AMERICA, INC.

• Remove the timing chain (1)  .
• Remove the tensioning rail (2)  from the bearing journal (3)  .
  NOTE: Do not disassemble the bearing journal (3).

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• Position the special tool 2 357 904  on the guide pin (arrow) of the crankshaft and secure it with the bolt (2) on the crankcase.
• Slacken the screw (1)  .

  Courtesy of BMW OF NORTH AMERICA, INC.

• Carefully press in the chain tensioner piston (3)  to the stop using a screwdriver (2)  and secure with the special tool 0 491 012 (11 4120). 
• Unscrew the bolts (1)  and carefully remove the chain tensioner.

  Courtesy of BMW OF NORTH AMERICA, INC.

• Loosen both bearing journals (1)  .
• Remove the guide rail (2)  .
• Loosen the bearing journals (4)  .
• Remove the tensioning rail (3)  .

  Courtesy of BMW OF NORTH AMERICA, INC.

• Loosen screw (1)  and remove the camshaft sprocket (2)  .

  Courtesy of BMW OF NORTH AMERICA, INC.

• Unscrew the bolt (2) and remove the special tool 2 357 904  .
• Remove the timing chain (1)  .

  Courtesy of BMW OF NORTH AMERICA, INC.