18 32 060 Removing and installing/renewing catalytic converters for cylinders 5-8 (N63)

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

Necessary preliminary tasks:

Remove upper HEAT SHIELD .
Remove the UNITS COMPARTMENT PARTITION WALL .
Remove EXHAUST SYSTEM .
Remove VACUUM PUMP .
Remove left and right monitoring sensor. See REPLACING LEFT MONITORING SENSOR (N63O1) and REPLACING RIGHT MONITORING SENSOR (N63O1) .

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

Screw (1) is located between the catalytic converters.

Tightening torque 18 31 3AZ .

Fig 1: Identifying Heat Shields And Screw

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

Tightening torque 18 31 3AZ .

Fig 2: Identifying Heat Shield Screw (Bottom Right)

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Release screw (1) on right heat shield.

Tightening torque 18 31 3AZ .

Unclip and remove the right heat shield.

Fig 3: Identifying Screws On Right Heat Shield

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

Tightening torque 18 31 3AZ .

Fig 4: Identifying Screw On Heat Shield At Bottom Left

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Release screw (1) on right left shield.

Tightening torque 18 31 3AZ .

Unclip and remove the heat shield (2) on the left.

Fig 5: Identifying Screw On Right Left Shield

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Release screws (1).

Tightening torque 18 32 2AZ .

Fig 6: Identifying Screws

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Release screws (1).

Tightening torque 18 32 2AZ .

Fig 7: Identifying Screws

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NOTE: Graphic 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 8: Identifying Screws On Catalytic Converter Cylinders

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NOTE: Graphic shows the engine removed.

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

Tightening torque 18 32 3AZ .

Fig 9: Identifying Screws On Catalytic Converter, Cylinders 5-8

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

Tightening torque 18 32 3AZ .

Fig 10: Identifying Screws On Catalytic Converter Cylinders 1-4

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

Tightening torque 18 32 3AZ .

Fig 11: Identifying Screws On Catalytic Converter, Cylinders 5-8, Rear

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Release screws (1) and (3).

Tightening torque 18 32 1AZ .

Remove and replace clamps (2) and (4).

Installation note:

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

Fig 12: Identifying Clamps And Screws

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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 13: Identifying Gap Between Ends Of V-Band Clamps

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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 14: Identifying Misalignment Of V-Band Clamp Ends

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

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

Fig 15: Identifying Catalytic Converters

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Installation note:

Graphic shows the engine removed.

Replace the seals (1) on the exhaust turbocharger.

Fig 16: Identifying Seals On Exhaust Turbocharger

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Assemble engine.

Check exhaust system for leak tightness.