18 12 031 Replacing rear silencer (N20, N26)

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2016 BMW 328i xDrive, 2016 BMW 328d xDrive, 2015 BMW 328i xDrive, 2015 BMW 328d xDrive, and 2014 BMW 328i xDrive. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Risk of burning!
Only perform this repair work after the exhaust system has cooled down.

Necessary preliminary tasks:

Support rear silencer with suitable jack and secure against falling down.
F23, F31, F33, F34, F36 only:
Remove right TRAILING LINK .

NOTE: If the separation point line is not marked by a punch mark in the pipe, determine the separation point by means of the pipe length on the new rear silencer.
Carry over separation point to faulty rear silencer and mark.

Secure rear silencer against falling off.

Cut through exhaust pipes at marked point with a suitable tool.

Fig 1: Identifying Exhaust Pipes Marked Point

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Unfasten nut.

Tightening torque 18 31 5AZ .

Fig 2: Identifying Nut

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Unlock connector (1) and remove.

Slacken nut (2).

Tightening torque 18 31 5AZ .

Lower and remove rear silencer.

Remount the ACTUATOR DRIVE for the exhaust flap on the new rear silencer.

Fig 3: Identifying Connector And Nut

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Installation note:

Adapt new rear silencer and connect using clamp.

Align clamping sleeves so that:

Nuts point downwards.
Cutting line is in middle of clamping sleeve.
There is sufficient spacing to adjoining components.

Center clamp and tighten down.

Tightening torque 18 31 4AZ .

Fig 4: Identifying Nitrogen Oxide Catalytic Converter

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NOTE: Check rubber mount for damage.
Replace damaged rubber mount.
Check exhaust system for leaks.