BMW 7 Series: Removing And Installing/Renewing Catalytic Converter Cylinder 5-8 (N63)

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

Necessary preliminary work

• Remove ACOUSTIC COVER.
• REMOVE BOTH INTAKE SILENCER HOUSINGS.
• Remove EXHAUST SYSTEM.
• Remove both control sensors.
• Remove both monitoring sensors.

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. 24: Identifying Screws And Cable Clips On Left And Right

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. 25: Identifying Rubber Mounts, Cable Clip And Heat Shield At Top

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

This is described further below in the instructions.

Release screw (2) on catalytic converter.

Tightening torque 18 32 4AZ.

Release clamp (3) on catalytic converter.

Replace clamp (3).

Tightening torque 18 32 1AZ.

Installation note: The clamp (3) must be installed with the screw toward the inside (illustration). Otherwise, the heat shield can no longer be installed on top.

Fig. 26: Identifying Heat Shield At Rear Left And Right, Clamp With Screw On Catalytic Converter

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

Tightening torque 18 32 1AZ.

Fig. 27: Identifying V-Band Clamps

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. 28: Locating V - Band Clamps Gap

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. 29: Locating V - Band Clamps Position

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

Screw (1) is located between the catalytic converters.

Fig. 30: Identifying Screws On Heat Shields And Catalytic Converter

NOTE: Picture shows the engine removed.

Release screws (1) on left heat shield.

Unclip left heat shield and remove.

Fig. 31: Removing Screws Of Left Heat Shield

NOTE: Picture shows the engine removed.

Release screw (1) on right heat shield.

Fig. 32: Identifying Screw Of Right Heat Shield

NOTE: Picture shows the engine removed.

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

Unclip heat shield and remove.

Fig. 33: Identifying Screw Of Heat Shield At Bottom Right

Release screws (1).

Detach hose (2) from cylinder head cover.

Release screws (3) on holder.

Tightening torque 18 32 2AZ.

Fig. 34: Identifying Hose Of Cylinder Head Cover And Screws On Holder

NOTE: Picture shows the engine removed.

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

Tightening torque 18 32 3AZ.

Remove catalytic converter for cylinders 5-8.

Fig. 35: Identifying Screws On Catalytic Converter

Installation note: Picture shows the engine removed.

Replace gasket (1) on left exhaust turbocharger.

Fig. 36: Identifying Gasket On Left Exhaust Turbocharger

Installation note: Clean sealing surfaces.

Replace gasket (1).

Fig. 37: Identifying Gasket

Assemble engine.

Check exhaust system for leak tightness.

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