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Home >> BMW >> 2009 >> X5 48i >> Repair and Diagnosis >> External Pages >> Different car >> Section 1317 (Engine - Repair Instructions (N73)) >> 25 Piston With Rings and >> 11 25 530 Removing and Installing/Replacing All Pistons (N73) >> Special tools required:

Special tools required:

WARNING: This page is about a different car, the 2008 BMW 760Li and 2007 BMW 760Li. However, it is still accessible from the selected car via links, so may be relevant.

Necessary preliminary tasks: 

IMPORTANT: Re-install piston, connecting rod and bearing shells back in the same position and in the same installation location.
Conrods and conrod bearing caps are denoted with the same pairing letters.
Do not mix them up as this will cause engine damage. 

Unscrew conrod bearing cover.

Set down conrod bearing caps in order.

NOTE: All conrods are cracked.
Do not mix up conrods and conrod bearing caps, observe pairing letters.
Fig 1: Identifying Bearing Caps Bolts
G04739767Courtesy of BMW OF NORTH AMERICA, INC.

Fit special tools 11 8 151 and 11 8 152. See 11 8 150 INSERTION TOOL

Remove conrod with piston from cylinder head side.

IMPORTANT: Do not damage cylinder wall when pulling out conrod with piston.
Fig 2: Identifying Special Tools (11 8 151 And 11 8 152)
G04773658Courtesy of BMW OF NORTH AMERICA, INC.

When removing and installing pistons with conrods, make sure piston cooling spray nozzles (1) are not bent.

Risk of damage. 

Fig 3: Identifying Piston Cooling Spray Nozzles
G04739766Courtesy of BMW OF NORTH AMERICA, INC.

Lift out retaining ring and press out piston pin.

IMPORTANT: Piston and piston pins are paired and must not be fitted individually.
Fig 4: Pressing Retaining Ring
G04773660Courtesy of BMW OF NORTH AMERICA, INC.

The piston pin must be able to be pressed through the liner by hand with little force and must not display any significant play.

Installation: 

The conrods can also be replaced individually.

Fig 5: Pressing Out Piston Pin
G04739770Courtesy of BMW OF NORTH AMERICA, INC.

Prior to installation, measure piston installation clearance: Measure piston diameter with micrometer at measuring point A from bottom edge of piston and offset at 90° to the axis of the piston pin.

Measuring point A.

Fig 6: Measuring Point A From Bottom Of Piston
G04739771Courtesy of BMW OF NORTH AMERICA, INC.

Adjust micrometer to cylinder bore of engine block. Set internal caliper on micrometer to zero. Measure bottom, center and top of cylinder bore in direction of travel and direction of engine rotation.

Diameter of cylinder bore.

Piston installation clearance.

Total permissible wear tolerance.

Fig 7: Measuring Cylinder Bore
G04739772Courtesy of BMW OF NORTH AMERICA, INC.

Due to the design of the piston head and the piston pin offset, the pistons are constructed specifically for each cylinder bank and must not be mixed up. 

IMPORTANT: Risk of damage.
Fig 8: Identifying Piston Head
G04773664Courtesy of BMW OF NORTH AMERICA, INC.

Cylinder bank 1 to 6. 

Fit conrod with piston pin to piston in such a way that arrow on piston points to front and flat end of conrod points to rear.

IMPORTANT: Conrods for cylinders 1 to 6 and 7 to 12 must be fitted differently to the pistons.
Fig 9: Identifying Special Tools (11 8 151 And 11 8 152)
G04773665Courtesy of BMW OF NORTH AMERICA, INC.

Cylinder bank 7 to 12. 

Fit conrod with piston pin to piston in such a way that arrow on piston points to front and flat end of conrod points to front. 

Install conrod bearing.

Fig 10: Identifying Cylinder Bank 7 To 12
G04773666Courtesy of BMW OF NORTH AMERICA, INC.

Install retaining ring.

Fig 11: Identifying Retaining Ring
G04739775Courtesy of BMW OF NORTH AMERICA, INC.

Insert special tools 11 8 151 and 11 8 152 in conrod. See 11 8 150 INSERTION TOOL

Lightly coat pistons and piston rings with oil.

Offset the contact points of the piston rings by approx. 120° to each other but do not position above the piston boss.

Press together piston rings using special tool 11 7 280. See 11 7 280 PLIERS

IMPORTANT: Danger of piston ring failure.
Fig 12: Identifying Special Tools (11 8 151 And 11 8 152) On Piston Rings
G04773668Courtesy of BMW OF NORTH AMERICA, INC.

Keep piston rings pressed with special tool 11 7 280. See 11 7 280 PLIERS

Install pistons with arrows pointing towards camshaft drive.

IMPORTANT: Danger of piston ring failure. 
Only press pistons into place with finger force - do not knock in!
Fig 13: Identifying Special Tool (11 7 280)
G04773669Courtesy of BMW OF NORTH AMERICA, INC.

Fit conrod with special tool 11 8 151 and 11 8 152 on crank pin. See 11 8 150 INSERTION TOOL

Remove special tools 11 8 151 and 11 8 152. See 11 8 150 INSERTION TOOL

Fig 14: Identifying Special Tool (11 8 151 And 11 8 152) On Crank Pin
G04773670Courtesy of BMW OF NORTH AMERICA, INC.
IMPORTANT: Conrods and conrod bearing caps are denoted with the same pairing letters (1), do not mix them up.

For purposes of clarity, the pairing letters (1) are shown on the removed conrod.

Fig 15: Aligning Connecting Rod Bearing Same Pairing Letters
G04739781Courtesy of BMW OF NORTH AMERICA, INC.

Apply light coat of oil to connecting-rod bearing shells.

NOTE: All conrods are cracked.
Do not mix up conrods and conrod bearing caps.
IMPORTANT: During installation, make sure conrod bearing caps are correctly seated.
Risk of damage. 

Install new conrod bolts.

Fig 16: Identifying Bearing Caps Bolts
G04739767Courtesy of BMW OF NORTH AMERICA, INC.

Tighten down conrod bolts with special tool 00 9 120. See 00 9 120 TORQUE ANGLE MEASURING DIAL

Installation: 

Tightening torque 11 24 1AZ. See 11 24 CONNECTING RODS AND BEARINGS

Fig 17: Identifying Special Tool (00 9 120) On Bearing Caps Bolts
G04739762Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine in reverse sequence to its disassembly.

Installation: 

Lubricate all crankshaft bearing positions with engine oil.

NOTE: The pistons are available in two oversizes for subsequent treatment of the cylinders.
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