18 32 050 Removing and replacing the catalytic converter cylinder 1-4 (N63)

WARNING: This page is about a different car, the 2013 BMW 550i GT, 2012 BMW 550i GT, 2011 BMW 550i GT, and 2010 BMW 550i GT. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Risk of burning!
Only perform this repair work on an engine that has cooled down.

Necessary preliminary work

Remove acoustic cover . See 11 00 REMOVING AND INSTALLING/REPLACING THE ACOUSTIC COVER (N63 B44 O 0/1) or 11 00 REMOVING AND INSTALLING/REPLACING ACOUSTIC COVER (N63)

Remove BOTH INTAKE SILENCER HOUSINGS.

Remove EXHAUST SYSTEM.

REMOVE BOTH CONTROL SENSORS.

Remove both monitoring sensors . See 11 78 540 REPLACING LEFT MONITOR SENSOR (N63) or 11 78 543 REPLACING RIGHT MONITOR SENSOR (N63) .

Picture shows the left side, carry out the operation for the right side in an identical way.

Release screws (1).

Remove cable clips on left and right.

Fig 1: Identifying Cable Clips And Screws

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Remove rubber mounts (1) and release screws underneath.

Tightening torque 13 71 5AZ.

Remove cable clip (2).

Remove the HEAT SHIELD (3) at top.

Fig 2: Identifying Rubber Mounts, Heat Shield And Cable Clip

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Remove heat shield (1) at rear left and right.

This is described further below in the instructions.

Release screws (2) on catalytic converter.

Tightening torque 18 32 4AZ.

Loosen the clamps (3) from the catalytic converter.

Replace clamps (3).

Tightening torque 18 32 1AZ.

Fig 3: Identifying Heat Shield, Catalytic Converter Clamp And Screw

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Installation note:

Clamps must be installed with the screws toward the inside (Figure). Otherwise, a top heat shield can no longer be installed.

Installation note:

The ends of the V-band clamps must rest parallel to each other.

Tightening torque 18 32 1AZ.

Fig 4: Identifying V-Band Clamps

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Installation note:

If you can see a gap between the ends of the V-band clamps, release and then repeat the screw connection.

Tightening torque 18 32 1AZ.

Fig 5: Identifying V-Band Clamps Gap

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Installation note:

If the ends of the V-band clamps are positioned under each other, release and then repeat the screw connection.

Tightening torque 18 32 1AZ.

Fig 6: Locating V-Band Clamps End

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Release screw (1) from heat shields (2) and (3).

Screw (1) is located between the catalytic converters.

Fig 7: Identifying Catalytic Converter And Heat Shield Screws

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NOTE: Picture shows the engine removed.

Release screws (1) on left heat shield.

Unclip left heat shield and remove.

Fig 8: Removing Left Heat Shield Screws

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NOTE: Picture shows the engine removed.

Release screw (1) on right heat shield.

Fig 9: Identifying Right Heat Shield Screw

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NOTE: Picture shows the engine removed.

Release screw (1) on heat shield at bottom right.

Unclip heat shield and remove.

Fig 10: Identifying Heat Shield Screw

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Picture shows the left side, carry out the operation for the right side in an identical way.

Release screws (1).

Detach hose (2) from cylinder head cover.

Release screws (3) on holder.

Tightening torque 18 32 2AZ.

Fig 11: Identifying Cyinder Head Cover Hose And Holder Screw

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NOTE: Picture shows the engine removed.

Loosen screws (1) on the catalytic converter cylinders 1-4 on the back of the cylinder head.

Tightening torque 18 32 3AZ.

Fig 12: Identifying Catalytic Converter Cylinder Mounting Screws (Back Of Cylinder Head)

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NOTE: Picture shows the engine removed.

Release screws (1) on catalytic converter, cylinders 5-8, rear, at cylinder head.

Tightening torque 18 32 3AZ.

Fig 13: Identifying Catalytic Converter Cylinder Mounting Screws (At Cylinder Head)

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NOTE: To remove the catalytic converter cylinders 1-4, it is necessary to remove the catalytic converter cylinders 5-8.

Remove catalytic converter for cylinders 5-8 (1).
Remove catalytic converter for cylinders 1-4 (2).

Fig 14: Identifying Catalytic Converters
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Installation note:

Picture shows the engine removed.

Replace the seals (1) on the exhaust turbocharger.

Fig 15: Identifying Turbocharger Gasket

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Installation note:

Picture shows the left side, the procedure for the right side is identical.

Clean sealing surfaces.

Replace gasket (1).

Fig 16: Identifying Gasket

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Assemble engine.

Check exhaust system for leak tightness.