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Home >> BMW >> 2000 >> 323Ci 2D Convertible, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 182 (Engine - Repair (S54)) >> Piston With Rings & Pins >> 11 25 530 Removing and installing/replacing all pistons (S54) >> Differentiating features:

Differentiating features:

WARNING: This page is about a different car, the 2002 BMW M Roadster, 2002 BMW M Coupe, 2001 BMW M Roadster, and 2001 BMW M Coupe. However, it is still accessible from the selected car via links, so may be relevant.
  1. Conrod bolt with M11x1.25 thread

    Bolt head: bihexagonal 12 mm A/F

  2. Conrod bolt with M10x1.25 thread

    Bolt head: Torx E12

    Fig 1: Identifying Conrod Bolts
    G03190715Courtesy of BMW OF NORTH AMERICA, INC.
CAUTION: The procedure for replacing the conrod bolts and the tightening specifications are different. Mixing up the procedure for replacing the conrods and conrod bolts and the tightening specifications will result in serious engine damage.
CAUTION: In S54 engine with the M10x1.25 conrod bolt (B) the conrod bolts must be replaced. Conrod bolts (B) are made from a material which only reaches its maximum strength after they have been tightened at least three times but no more than five times.
Fig 2: Identifying M10x1.25 Conrod Bolt
G00397773Courtesy of BMW OF NORTH AMERICA, INC.
CAUTION: Contrary to the instructions for all other BMW engines, the conrod bolts must NOT be replaced in the S54 engine with the M11x1.25 conrod bolt. The M11x1.25 may only be reused in the same conrod thread. Conrods with M11x1.25 are no longer supplied as replacements.
If a conrod or a conrod bolt with M11x1.25 thread is damaged: replace the conrods with a complete set of conrods with M10x1.25  conrod bolts.
Fig 3: Identifying M11x1.25 Conrod Bolt
G00397775Courtesy of BMW OF NORTH AMERICA, INC.
Fig 4: Removing M10x1.25 Conrod Bolt
G00397774Courtesy of BMW OF NORTH AMERICA, INC.
Fig 5: Removing M11x1.25 Conrod Bolt
G00397776Courtesy of BMW OF NORTH AMERICA, INC.

Insert special tool in conrod. Remove connecting rod with piston from cylinder-head side. For M10x1.25 conrod bolt, use 11 2 050. For M11x1.25 conrod bolt, use 11 3 480.

Fig 6: Removing M10x1.25 Conrod Bolt Connecting Rod
G00397777Courtesy of BMW OF NORTH AMERICA, INC.
Fig 7: Removing M11x1.25 Conrod Bolt Connecting Rod
G00397778Courtesy of BMW OF NORTH AMERICA, INC.
CAUTION: Piston and piston bolts are paired and must not be fitted individually.

Lift out retaining ring and press out piston pin.

Fig 8: Removing Retaining Ring & Piston Pin
G00397779Courtesy of BMW OF NORTH AMERICA, INC.