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 provided only at one component. The procedure is the same for all other 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 TOPPING (1) points to the top to the combustion chamber.
If there is no assembly mark TOPPING (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 arrow direction 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 arrow direction 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 THE PISTONS WITH THE CONNECTING ROD .
Refer to INSTALLING THE OIL DEFLECTOR .
Refer to INSTALLING THE OIL VACUUM PUMP .
Refer to REFITTING OIL PAN .
Refer to INSTALLING BEARING BRACKET .
Refer to INSTALLING FRONT AXLE DIFFERENTIAL .
Refer to SEALING THE OIL DUCT .
Refer to CLEANING SEALING SURFACES .
Refer to INSTALLING THE CYLINDER HEAD GASKET .
Refer to BLOCKING THE CRANKSHAFT IN THE TDC FIRING POSITION OF CYLINDER 1 .
Refer to INSTALLING THE CYLINDER HEAD .
Refer to ADJUSTING THE CAMSHAFTS WITH THE SPECIAL TOOL .
Refer to INSTALLING THE INTAKE ADJUSTER .
Refer to INSTALLING THE VANOS CENTRAL VALVE OF THE INTAKE ADJUSTER .
Refer to INSTALLING EXHAUST CAMSHAFT ADJUSTER .
Refer to INSTALLING THE VANOS CENTRAL VALVE OF THE EXHAUST CAMSHAFT ADJUSTER .
Refer to PRE-TENSIONING 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 INSTALLING CHAIN TENSIONER .
Refer to CHECKING THE TIMINGS OF THE CAMSHAFT .
Refer to INSTALLING THE COOLANT LINE BETWEEN THE CYLINDER HEAD AND THE COOLANT PUMP .
Refer to INSTALLING THE OIL RETURN LINE FOR THE EXHAUST TURBOCHARGER .
Refer to INSTALLING CYLINDER HEAD COVER .
Refer to INSTALLING BOTH ACTUATORS .
Refer to PREPARING THE INJECTORS FOR INSTALLATION .
Refer to INSTALLING THE HIGH-PRESSURE RAIL WITH INJECTORS OF THE CYLINDERS 4 TO 6 .
Refer to INSTALLING THE HIGH-PRESSURE RAIL WITH INJECTORS OF THE CYLINDERS 1 TO 3 .
Refer to INSTALLING THE HIGH-PRESSURE LINE BETWEEN THE HIGH-PRESSURE PUMP AND THE HIGH-PRESSURE RAIL .
Refer to INSTALLING HIGH PRESSURE PUMP .
Refer to INSTALLING ALL SPARK PLUGS .
Refer to INSTALLING ALL IGNITION COILS .
Refer to INSTALLING CATALYTIC CONVERTER .
Refer to INSTALLING THE OXYGEN SENSOR MONITOR .
Refer to INSTALLING LAMBDA OXYGEN SENSOR .
Refer to INSTALLING THE INTAKE PLENUM .
Refer to INSTALLING THE TANK VENT VALVE .
Refer to INSTALLING ENGINE VENTILATION LINE .
Refer to INSTALLING ACOUSTIC COVER AT REAR .
Refer to FILLING ENGINE OIL .
Refer to OPENING THE OIL FILLER CAP .
Refer to REMOVING THE ENGINE FROM THE ASSEMBLY JIG .
Refer to MOUNTING THE ENGINE ON THE FRONT AXLE .
Refer to INSTALLING THE COMPLETE FRONT AXLE WITH THE ENGINE AND TRANSMISSION .