18 32 050 Removing And Installing/Replacing Catalytic Exhaust Gas Converter, Cylinders 5-8 (N63)

Necessary preliminary tasks: 

• Remove acoustic cover by raising cover in upward direction.
Fig 1: Removing Acoustic Cover
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• Remove both intake filter housings  . See 13 71 030 REMOVING AND INSTALLING BOTH INTAKE FILTER HOUSINGS (N63) .
• Remove exhaust system  . See 18 00 020 REMOVING AND INSTALLING COMPLETE EXHAUST SYSTEM (N63) .
• Remove both connecting pipes  . See 18 32 605 REMOVING AND INSTALLING/REPLACING BOTH CONNECTING PIPES ON CATALYTIC CONVERTER (N63) .
• Remove both control sensors  . See 11 78 533 REPLACING RIGHT CONTROL SENSOR (N63) and 11 78 530 REPLACING LEFT CONTROL SENSOR (N63) .
• Remove both monitor sensors  . See 11 78 540 REPLACING LEFT MONITOR SENSOR (N63) and 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 holders on left and right.

Fig 2: Identifying Cable Holders And Screws

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Remove rubber mounts (1) and release screws underneath.

Tightening torque. See 13 71 5AZ in 13 71 AIR INTAKE DUCT .

Remove cable holder (2).

Remove heat shield  (3) at top. See 11 65 180 REMOVING AND INSTALLING/REPLACING HEAT SHIELD AT TOP (N63) .

Fig 3: Identifying Rubber Mounts And Cable Holder

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

This is described further below in the instruction.

Release screw (2) on catalytic converter.

Tightening torque. See 18 32 4AZ in 18 32 CATALYTIC EXHAUST GAS CONVERTER .

Release clamp (3) on catalytic converter.

Replace clamp (3).

Tightening torque. See 18 32 1AZ in 18 32 CATALYTIC EXHAUST GAS CONVERTER .

Installation: 

Clamp (3) must be fitted with the screw pointing inwards (shown in picture). Otherwise it will not be possible to install the heat shield at the top.

Fig 4: Identifying Clamp And Screw

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Installation: 

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

Tightening torque. See 18 32 1AZ in 18 32 CATALYTIC EXHAUST GAS CONVERTER .

Fig 5: Identifying V-Band Clamps

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Installation: 

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

Tightening torque. See 18 32 1AZ in 18 32 CATALYTIC EXHAUST GAS CONVERTER .

Fig 6: Tightening V-Band Clamps

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Installation: 

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

Tightening torque. see 18 32 1AZ in 18 32 CATALYTIC EXHAUST GAS CONVERTER .

Fig 7: Locating V-Band Clamps

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

Screw (1) is located between catalytic exhaust-gas converters.

Fig 8: Identifying Heat Shields And Screw

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Release screws (1) on left heat shield.

Unclip left heat shield and remove.

Fig 9: Identifying Left Heat Shield And Screws

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Release screw (1) on right heat shield.

Fig 10: Identifying Right Heat Shield And Screw

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

Unclip heat shield and remove.

Fig 11: Identifying Heat Shield And Screw

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Release screws (1).

Detach hose (2) from cylinder head cover.

Release screws (3) on holder.

Tightening torque. See 18 32 2AZ in 18 32 CATALYTIC EXHAUST GAS CONVERTER .

Fig 12: Identifying Cylinder Head Cover Hose And Screws

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

Tightening torque. See 18 32 3AZ in 18 32 CATALYTIC EXHAUST GAS CONVERTER .

Remove catalytic converter for cylinders 5-8.

Fig 13: Identifying Catalytic Converter And Screws

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Installation: 

Picture shows the engine removed.

Replace gasket (1) on left turbocharger.

Fig 14: Identifying Turbocharger

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Assemble engine.

Check exhaust system for leaks.