Install the piston rings

NOTE: RISK OF DAMAGE
Very wide spreading of the piston rings during installation/removal.
Damage to the piston rings.

Spread the piston rings only until the piston ring can just be slid over the piston.
Use piston ring pliers to install and remove the piston rings.

NOTE: TECHNICAL INFORMATION
Clean the used pistons carefully . Do not use a metal-cutting tool to avoid damaging the pistons.

NOTE: TECHNICAL INFORMATION
Wear safety goggles.

NOTE: The description is for one component only. The procedure is identical for all further components.

Determining the correct set of the piston ring (1) (see applicable BMW parts catalogue):

Engine	Set of piston rings	Pistons
B38M1 ECE	8 693 017	8 678 931
B38M1 ECE	8 693 017	9 494 399
B48M1 ECE	8 693 017	8 678 931
B48M1 ECE	8 693 017	9 494 399
B38M1 CN	8 693 017	8 678 931
B38M1 CN	9 847 276	8 681 079
B48M1 CN	8 693 017	8 678 931
B48M1 CN	9 847 276	8 681 079
B48O1 ECE+CN	8 693 017	8 678 934
B48T1 ECE+CN	9 846 014	9 488 343
B58M1	9 847 276	8 681 079
B58O1	9 693 017	8 678 934

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Keep the standard piston ring pliers (1) ready.

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Correctly prepare the piston rings:
Upper piston ring (1): Plain rectangular compression ring (engraving must point upwards)

Center piston ring (2): Taper faced piston ring (engraving must point upwards)

Oil scraper ring (3): consists of 2 piston rings ((O1), (O3)) with a spring (O2) in the center.

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Make sure that the assembly mark TOP (1) points to the top to the combustion chamber.
If there is no assembly mark TOP (1), then the piston ring with the writing must point to the top to the combustion chamber.

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Attach the oil scraper rings (1) and springs (2) manually (see following steps).

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Slide the spring (1) on to the piston (2) and install it.

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Slide the two oil scraper rings (1) on to the piston (2) and install them.

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Position the center piston ring (1) in the marked area at the piston ring pliers (2).

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Clamp the piston ring pliers (1) in the direction of arrow and feed in the center piston ring (2) in the piston (3) and install it.

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Release the piston ring pliers (1) at the center piston ring (2).
Feed out the piston ring pliers (1) at the center piston ring (2) and remove it.

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Position the upper piston ring (1) in the marked area at the piston ring pliers (2).

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Clamp the piston ring pliers (1) in the direction of arrow and feed in the upper piston ring (2) in the piston (3) and install it.

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Release the piston ring pliers (1) at the upper piston ring (2).
Feed out the piston ring pliers (1) at the upper piston ring (2) and remove it.

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Follow-up Work

Refer to INSTALLING ALL PISTONS WITH CONNECTING ROD .
Refer to INSTALLING THE OIL DEFLECTOR
Refer to INSTALL THE OIL VACUUM PUMP .
Refer to REFITTING SUMP .
Refer to INSTALL BEARING SUPPORT
Refer to INSTALL FRONT AXLE DIFFERENTIAL
Refer to INSTALLING THE FLYWHEEL .
Refer to INSTALLING THE ACOUSTIC COVER FOR THE OIL SUMP .
Refer to BLOCKING THE CRANKSHAFT IN THE TDC FIRING POSITION OF CYLINDER 1 .
Refer to SEAL THE OIL DUCT .
Refer to CLEAN SEALING SURFACES .
Refer to REPLACE CYLINDER HEAD GASKET .
Refer to INSTALLING THE CYLINDER HEAD .
Refer to ADJUST THE CAMSHAFTS WITH THE SPECIAL TOOL .
Refer to INSTALL EXHAUST CAMSHAFT ADJUSTER .
Refer to INSTALLING THE INTAKE ADJUSTER .
Refer to INSTALL THE VANOS CENTRAL VALVE OF THE INTAKE ADJUSTER .
Refer to INSTALLING THE VANOS CENTRAL VALVE OF THE EXHAUST CAMSHAFT ADJUSTER .
Refer to PRETENSION THE TIMING CHAIN WITH THE SPECIAL TOOL .
Refer to TIGHTENING THE VANOS CENTRAL VALVE OF THE EXHAUST CAMSHAFT ADJUSTER .
Refer to TIGHTENING THE VANOS CENTRAL VALVE OF THE INTAKE ADJUSTER .
Refer to DISASSEMBLING ALL SPECIAL TOOLS
Refer to INSTALL CHAIN TENSIONER .
Refer to CHECKING CAMSHAFT TIMING .
Refer to INSTALLING THE OIL RETURN LINE FOR THE EXHAUST TURBOCHARGER .
Refer to INSTALL THE COOLANT RETURN LINE FOR THE EXHAUST TURBOCHARGER .
Refer to INSTALLING COOLANT FEED LINE FOR EXHAUST TURBOCHARGER .
Refer to INSTALLING CYLINDER HEAD COVER .
Refer to INSTALLING BOTH ACTUATORS .
Refer to PREPARE THE INJECTORS FOR INSTALLATION .
Refer to INSTALLING THE RAIL WITH INJECTORS .
Refer to INSTALLING THE HIGH PRESSURE PUMP .
Refer to INSTALLING HIGH PRESSURE LINE BETWEEN RAIL AND HIGH PRESSURE PUMP .
Refer to INSTALLING ALL SPARK PLUGS .
Refer to INSTALLING THE INTAKE PLENUM .
Refer to INSTALLING THE TANK VENT VALVE .
Refer to TOPPING UP THE ENGINE OIL .
Refer to CHECK/ADD FRONT AXLE TRANSMISSION OIL .
Refer to REMOVING THE ENGINE FROM THE ASSEMBLY STAND
Refer to INSTALL ENGINE .