11 25 671 Replacing piston rings on all pistons (M62)

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 BMW 540i, 2002 BMW 540i, 2001 BMW 540i, 2000 BMW 540i, and 1999 BMW 540i. 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.

NOTE: It might not be possible to find the identification on used piston rings.
Put aside piston rings in correct sequence and installation position.
New pistons may only be installed together with new piston rings.

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

Courtesy of BMW OF NORTH AMERICA, INC.

Installation

Insert piston rings with the word "TOP" facing piston crown.

Plain compression ring
Stepped taper-face ring "TOP"
Three-piece steel band ring

Arrange piston ring contact points with offset of approx. 120° to one another, but not over piston pin eye.

Fig 2: Identifying Piston Ring Gap

Courtesy of BMW OF NORTH AMERICA, INC.

End float, refer to ENGINE - TECHNICAL DATA - 540I (E39) .

Fig 3: Checking Piston Ring Groove Gap Using Filler Gauge

Courtesy of BMW OF NORTH AMERICA, INC.

Gap in cylinder, refer to ENGINE - TECHNICAL DATA - 540I (E39) .

Fig 4: Checking Gap In Cylinder

Courtesy of BMW OF NORTH AMERICA, INC.