Muffler: Service and Repair
WM 263319 Removing and installing rear silencer - Turbo
Tools
Technical values
Preliminary work
1. Remove rear apron.
=> 635519 Removing and installing rear apron.
2. Remove charge air cooler (cylinder bank 1-3).
=> 214319 Removing and installing charge air cooler.
3. Remove bumper with heat shield.
=> 635019 Removing and installing rear bumper.
4. Remove heat shield from the catalytic converter (cylinder bank 1-3).
=> 635019 Removing and installing rear bumper.
5. Disconnect plug connection -1 and 2- for oxygen sensor cables at the left side of the engine compartment and expose lines.
Oxygen sensor connectors, cylinder bank 1-3
5.1. Unclip oxygen sensor lines -1 and 2- from the line brackets -arrows- and guide them through at the side of the engine to the catalytic converter.
Oxygen sensors at catalytic converter
Information
- It may only be supported over a large area at the oil pan.
- Localised loading is not permitted.
6. Support the engine.
6.1. Support the engine at the oil pan using hydraulic jack HH2 WE 1033 and GA passenger car transmission plate WE 1224.
6.2. Alternative to transmission jack plate:
Screw on the mounting peg 9163/2 in the middle using a wooden board (40 x 30 cm) and use it as a support.
Mounting peg
Information
- When lowering, the engine must not rest on the rear axle cross member.
7. Lower the engine.
7.1. Loosen two special M12 nuts (internal Torx, screw insert T55) -1- on the engine mounting (hydraulic mount) at the left and right.
Engine carrier to engine mounting on cylinder bank 4-6 (view from below)
7.2. Slowly lower the engine by about 40 mm (measured at the engine carrier) using hydraulic jack HH2 WE 1033.
Removing rear silencer - Turbo
Information
Specifications for wrench sizes (a/f specifications) for screw heads are described as follows:
- Torx screws: (E.) for external Torx, (T.) for internal Torx.
- Hexagon-head bolts (internal and external hexagon): Wrench size (a/f)
Component overview:
Component overview of exhaust system without manifold
CAUTION
Hot components
- Risk of burns
-> Let hot components cool down.
-> Wear personal protective gear.
1. Unscrew four M8 hexagon nuts (a/f 13) -1- on the catalytic converter flange for the turbocharger on cylinder bank 1-3.
Upper turbocharger flange threaded joint (cylinder bank 1-3)
View of lower threaded joint:
Lower turbocharger flange threaded joint (cylinder bank 1-3)
1.1. Remove heat shield on the catalytic converter.
2. Loosen rear silencer mounting.
2.1. Loosen clamp -1- on the connection point between the rear silencer and catalytic converter (cylinder bank 4-6).
2.2. Loosen restraining straps. To do this, loosen two M8 cheese head bolts (hexagon socket a/f 6) -2-.
Rear silencer mounting
2.3. Slide restraining straps out over the holder.
Restraining straps for rear silencer
Information
- The help of another person is required for removing and installing the silencer.
3. Remove the rear silencer and catalytic converter with the help of another person.
3.1. Loosen the catalytic converter (cylinder bank 1-3) from the threaded bolts on the turbocharger -arrow 1- and press it backwards.
3.2. Pull off the rear silencer and catalytic converter at the connection point for the catalytic converter on cylinder bank 4-6 -arrow 2-.
Removing rear silencer/catalytic converter for cylinder bank 1-3
4. Disconnect the removed rear silencer from the catalytic converter (cylinder bank 1-3).
4.1. To do this, loosen the clamp at the connection point between the rear silencer and catalytic converter.
5. Replace metal seal for turbocharger and four lock nuts.
6. Clean sealing faces and joints (on rear silencer and catalytic converter).
Installing rear silencer - Turbo
Information
Specifications for wrench sizes (a/f specifications) for screw heads are described as follows:
- Torx screws: (E.) for external Torx, (T.) for internal Torx.
- Hexagon-head bolts (internal and external hexagon): Wrench size (a/f)
1. Grease the screw thread and clamps with high-temperature grease Optimol Paste MF (Part No. 000.043.207.07) before installation.
Information
- The help of another person is required for removing and installing the silencer.
2. Pre-fit the catalytic converter (cylinder bank 1-3) on the removed rear silencer. Do not tighten the clamp yet.
3. Fit the rear silencer and catalytic converter for cylinder bank 1-3 on the catalytic converter for cylinder bank 4-6 -arrow 1-. Do not tighten clamp yet.
3.1. Get another person to hold the rear silencer.
Installing rear silencer/catalytic converter for cylinder bank 1-3
4. Fit a new metal seal on the turbocharger and slide the catalytic converter (cylinder bank 1-3) onto the threaded bolts on the turbocharger -arrow 2-.
4.1. Position heat shield at the threaded bolts.
4.2. Fit and tighten four M8 hexagon nuts (a/f 13) on the threaded bolts.
=> Tightening torque: 25 Nm (19 ftlb.)
5. Secure the rear silencer.
5.1. Position two restraining straps on the holder and tighten the two M8 cheese head bolts.
Restraining straps for rear silencer
=> Tightening torque: 15 Nm (11 ftlb.)
5.2. Tighten clamps -1- at the connection points between the rear silencer and catalytic converter.
Assembly position 45°, screw head facing backwards
Installation position of clamping sleeve
=> Tightening torque: 55 Nm (41 ftlb.)
Rear silencer mounting
6. Route electric lines for oxygen sensors -1 and 2-.
6.1. Guide the oxygen sensor lines at the side of the engine to the plug connections in the engine compartment and clip them into the line brackets -arrows-.
Oxygen sensors
6.2. Close the plug connections -1 and 2- for the oxygen sensors and clip the connectors into the holders.
Oxygen sensor connectors, cylinder bank 1-3
Subsequent work
1. Secure the engine.
1.1. Lift the engine into installation position using the hydraulic jack and guide the threaded bolts of the engine mounting into the engine carrier.
1.2. Tighten two special M12 nuts (internal Torx, screw insert T55) on the engine mounting (hydraulic mount) at the left and right.
=> Tightening torque: 85 Nm (63 ftlb.)
2. Install bumper and heat shield.
=> 635019 Removing and installing rear bumper.
3. Install heat protection panel on catalytic converter.
=> 635019 Removing and installing rear bumper.
4. Install charge air cooler.
=> 214319 Removing and installing charge air cooler.
5. Install the rear apron.
=> 635519 Removing and installing rear apron.