11 25 671 Replacing piston rings on all pistons (M52 / S52 / M52TU / M54 / M56)

(piston removed)

Remove piston rings with a piston-ring compressing pliers.

Fig 1: Removing Piston Rings With Piston-Ring Compressing Pliers

Courtesy of BMW OF NORTH AMERICA, INC.

NOTE: It might not be possible to find the identification on used piston rings.
Put aside piston rings in correct sequence and installation position.
Only install new pistons in conjunction with new piston rings.

Installation:

Install piston rings with "TOP" to piston top.

Plain compression ring
Stepped compression ring "Top"
Slotted oil ring with hose spring clip

Fig 2: Identifying Piston Rings
Courtesy of BMW OF NORTH AMERICA, INC.

Measure axial play, refer to ENGINE - TECHNICAL DATA .

Fig 3: Measuring Axial Play

Courtesy of BMW OF NORTH AMERICA, INC.

Measure end clearance, refer to ENGINE - TECHNICAL DATA .

Fig 4: Measuring End Clearance

Courtesy of BMW OF NORTH AMERICA, INC.