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

WARNING: This page is about a different car, the 2002 BMW Z3 and 2001 BMW Z3. However, it is still accessible from the selected car via links, so may be relevant.

(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 PISTON WITH RINGS AND PINS .

Fig 3: Measuring Axial Play

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Measure end clearance. Refer to PISTON WITH RINGS AND PINS .

Fig 4: Measuring End Clearance

Courtesy of BMW OF NORTH AMERICA, INC.