11 25 671 Replacing piston rings on all pistons (M57T2-SCR)

WARNING: This page is about a different car, the 2013 BMW X5, 2012 BMW X5, and 2011 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.

Installation note:

Removing PISTON .

Measure axial play. See 1125 PISTONS WITH RINGS AND PINS (M57T2/TOP/SCR/D30) .

Fig 1: Measuring Piston Rings Side Clearance

Courtesy of BMW OF NORTH AMERICA, INC.

Remove piston rings with piston ring 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.

Fig 2: Removing Piston Rings With Piston Ring Pliers

Courtesy of BMW OF NORTH AMERICA, INC.

Measure end clearance with a feeler gauge. See 1125 PISTONS WITH RINGS AND PINS (M57T2/TOP/SCR/D30) .

Fig 3: Checking Piston Ring End Clearance Using Feeler Gauge

Courtesy of BMW OF NORTH AMERICA, INC.

Installation note:

Install piston rings with "TOP" to piston crown.

Plain rectangular compression ring
Piston ring
Bevelled roof ring with spiral expander

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

Fig 4: Identifying Plain Rectangular Compression Ring And Piston Ring

Courtesy of BMW OF NORTH AMERICA, INC.

NOTE: Oil scraper ring comprises two steel band rings (1) and a bearing spring (2).

Installation note:

Insert bearing spring (2) into piston ring groove and then fit steel band rings (1) so that contact points are offset by approx. 120°.

Fig 5: Identifying Steel Band Rings And Bearing Spring

Courtesy of BMW OF NORTH AMERICA, INC.

Offset the contact points (1) of the piston rings by approx. 120° to each other but do not position above the gudgeon pin boss.

Illustration shows N52

Fig 6: Identifying Piston Contact Points

Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine.