Catalytic Converter: Service and Repair
WM 267319 Removing and installing catalytic converter - turbo engine
Tools
Technical values
Preliminary work
1. Remove rear apron.
-> 635519 Removing and installing rear apron .
2. Remove charge-air cooler.
-> 214319 Removing and installing charge-air cooler.
3. Remove heat shield over the catalytic converter.
-> 635019 Removing and installing rear bumper 635019 Removing and installing rear bumper.
4. Remove bumper with heat shield.
-> 635019 Removing and installing rear bumper 635019 Removing and installing rear bumper.
WARNING
Objects or loads falling down
- Risk of squashing or crushing
-> Secure components to prevent them from falling down.
Information
- It may only be supported over a large area at the oil pan.
- Localised loading is not permitted.
Information
- When lowering, the engine must not rest on the rear axle cross member.
5. Lower the engine.
5.1. Support the engine at the oil pan with a transmission jack.
Transmission and unit jack Junior Jack 2.0 WE 1223 ; GA passenger car transmission plate WE 1224
5.2. Loosen two M12 collar nuts (T55) on the rear engine mountings.
5.3. Slowly lower the engine using the transmission jack.
Removing catalytic converter
Removing catalytic converter - cylinder bank 1-3
CAUTION
Hot components
- Risk of burns
-> Let hot components cool down.
-> Wear personal protective gear.
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. Disconnect plug connection for electric lines for the oxygen sensors.
1.1. Unclip the oxygen sensor connectors (cylinder bank 1-3) -1 and 2- in the engine compartment and disconnect the plug connection.
Oxygen sensor connectors, cylinder bank 1-3
1.2. Guide the oxygen sensor lines -1 and 2- through at the side of the engine to the catalytic converter. To do this, unclip the cables from the holders -arrows-.
Oxygen sensors at catalytic converter
2. Loosen the rear silencer.
2.1. Loosen the clamp (M10 screw, a/f 15) -1- at the connection point between the rear silencer and catalytic converter (cylinder bank 4-6).
2.2. Loosen two M8 cheese head bolts (hexagon socket head, a/f 6) -2- for the restraining straps on the rear silencer. -arrow-
Rear silencer mounting
2.3. Slide the restraining straps outwards over the holder -arrow-.
Restraining straps for rear silencer
3. Loosen and screw off four M8 fastening nuts (a/f 13) -1- on the catalytic converter flange (cylinder bank 1-3) for the turbocharger.
3.1. Threaded joint on cylinder bank 1-3 at the top:
Turbocharger flange at the top on cylinder bank 1-3
3.2. Threaded joint on cylinder bank 1-3 at the bottom:
Turbocharger flange at the bottom on cylinder bank 1-3
3.3. Replace fastening nuts.
4. Pull the catalytic converter on cylinder bank 1-3 to the rear and off the studs on the turbocharger -arrow 1-.
4.1. Then pull the rear silencer together with the catalytic converter off the catalytic converter on cylinder bank 4-6 -arrow 2-.
4.2. Remove components with the help of another person.
Removing rear silencer/catalytic converter for cylinder bank 1-3
5. Disconnect the removed catalytic converter (cylinder bank 1-3) from the rear silencer by loosening the clamp and pulling off the catalytic converter.
Removing catalytic converter - cylinder bank 4-6
CAUTION
Hot components
- Risk of burns
-> Let hot components cool down.
-> Wear personal protective gear.
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. Disconnect plug connections for electric lines for the oxygen sensors.
1.1. Unclip and release the oxygen sensor connectors (cylinder bank 4-6) -1 and 2- in the engine compartment.
Oxygen sensor connectors, cylinder bank 4-6
1.2. Guide the oxygen sensor lines -1 and 2- through at the side of the engine to the catalytic converter. To do this, unclip the cables from the holders -arrows-.
Oxygen sensors at catalytic converter
2. Loosen the rear silencer.
2.1. Loosen the clamp (M10 screw, a/f 15) -1- at the connection point between the rear silencer and catalytic converter (cylinder bank 1-3).
2.2. Loosen two M8 cheese head bolts (hexagon socket head, a/f 6) -2- for the restraining straps.
Rear silencer
2.3. Slide the restraining straps outwards over the holder -arrow-.
Restraining straps for rear silencer
3. Loosen four M8 fastening nuts (a/f 13) -1- on the catalytic converter flange of the turbocharger on cylinder bank 4-6.
3.1. Threaded joint for catalytic converter flange at the top:
Turbocharger flange at the top on cylinder bank 1-3
3.2. Threaded joint for catalytic converter flange at the bottom:
Turbocharger flange at the bottom on cylinder bank 1-3
3.3. Replace fastening nuts.
4. Pull the catalytic converter (cylinder bank 4-6) to the rear and off the studs on the turbocharger -arrow 1-.
4.1. Then pull the rear silencer together with the catalytic converter off the catalytic converter on cylinder bank 1-3 -arrow 2-.
4.2. Remove components with the help of another person.
Removing rear silencer/catalytic converter for cylinder bank 1-3
5. Disconnect the removed catalytic converter (cylinder bank 4-6) from the rear silencer by loosening the clamp and pulling off the catalytic converter.
Installing catalytic converter
Installing catalytic converter - cylinder bank 1-3
CAUTION
Heavy components
- Risk of squashing
-> Wear personal protective gear.
-> Get someone to help if necessary.
1. Fit the catalytic converter (cylinder bank 1-3) on the removed rear silencer, but do not tighten the clamp yet.
2. Fit the rear silencer together with the catalytic converter (cylinder bank 1-3) on the catalytic converter on cylinder bank 4-6 -arrow 1- , but do not tighten the clamp yet.
2.1. Get another person to help you do this!
3. Replace the metal seal between the catalytic converter and exhaust manifold.
3.1. Slide the seal over the threaded bolts as far as the sealing face on the exhaust manifold.
4. Slide the catalytic converter onto the studs on the turbocharger (cylinder bank 1-3) -arrow 2-.
4.1. Get another person to support the rear silencer.
Installing rear silencer/catalytic converter (view of cylinder bank 1-3)
5. Secure the catalytic converter.
5.1. Screw in four new M8 fastening nuts (a/f 13) -1- on the catalytic converter flange of the turbocharger and tighten uniformly.
=> Tightening torque: 25 Nm (19 ftlb.)
Turbocharger flange at the top on cylinder bank 1-3
6. Secure the rear silencer.
6.1. Slide two restraining straps on the rear silencer onto the holder -arrow-.
Restraining straps for rear silencer
6.2. Position restraining straps with M8 cheese head bolts -2-.
Rear silencer mounting
6.3. Tighten both cheese head bolts.
=> Tightening torque: 15 Nm (11 ftlb.)
7. Tighten the clamps (M10 screw, a/f 15) -1- at the connection points between the rear silencer and catalytic converters.
=> Tightening torque: 55 Nm (41 ftlb.)
8. Route electric lines for oxygen sensors.
8.1. Guide oxygen sensor lines -1 and 2- at the side of the engine to the plug connections in the engine compartment and join the connectors.
Oxygen sensor connectors, cylinder bank 1-3
8.2. Clip oxygen sensor lines -1 and 2- into the line brackets -arrow-.
Oxygen sensors at catalytic converter
Installing catalytic converter - cylinder bank 4-6
CAUTION
Heavy components
- Risk of squashing
-> Wear personal protective gear.
-> Get someone to help if necessary.
1. Fit the catalytic converter (cylinder bank 4-6) on the removed rear silencer, but do not tighten the clamp yet.
2. Fit the rear silencer together with the catalytic converter (cylinder bank 4-6) on the catalytic converter on cylinder bank 1-3, but do not tighten the clamp yet.
2.1. Get another person to help you do this!
3. Replace the metal seal between the catalytic converter and exhaust manifold.
3.1. Slide the seal over the threaded bolts as far as the sealing face on the exhaust manifold.
4. Slide the catalytic converter (cylinder bank 4-6) onto the studs on the turbocharger -arrow 2-.
4.1. Get another person to support the rear silencer.
Installing rear silencer/catalytic converter (view of cylinder bank 1-3)
5. Secure the catalytic converter.
5.1. Screw in four new M8 fastening nuts (a/f 13) -1- on the catalytic converter flange of the turbocharger and tighten uniformly.
Tightening torque same as cylinder bank 1-3
Turbocharger flange at the top on cylinder bank 1-3
6. Secure the rear silencer.
6.1. Slide two restraining straps on the rear silencer onto the holder -arrow-.
Restraining straps for rear silencer
6.2. Position restraining straps with M8 cheese head bolts -2-.
Rear silencer mounting
6.3. Tighten both cheese head bolts.
Tightening torque same as cylinder bank 1-3
7. Tighten the clamps (M10 screw, a/f 15) -1- at the connection points between the rear silencer and catalytic converters.
8. Route electric lines for oxygen sensors.
8.1. Guide oxygen sensor lines at the side of the engine to the plug connections -1 and 2- in the engine compartment and join the connectors.
Oxygen sensor connectors, cylinder bank 4-6
8.2. Clip oxygen sensor lines -1 and 2- into the line brackets -arrows-.
Oxygen sensors at catalytic converter
Subsequent work
Information
- It may only be supported over a large area at the oil pan.
- Localised loading is not permitted.
WARNING
Objects or loads falling down
- Risk of squashing or crushing
-> Secure components to prevent them from falling down.
1. Raise and secure the engine.
1.1. Move the engine into installation position using the transmission jack by guiding the threaded bolts on the engine mountings through the engine carrier.
1.2. Fit and tighten two M12 collar nuts (T55) on the threaded bolts.
=> Tightening torque: 85 Nm (63 ftlb.)
1.3. Slowly lower the transmission jack and remove it from the work area.
2. Install bumper and heat shield.
-> 635019 Removing and installing rear bumper 635019 Removing and installing rear bumper.
3. Install heat shield on the catalytic converter.
-> 635019 Removing and installing rear bumper 635019 Removing and installing rear bumper.
4. Install charge-air cooler.
-> 214319 Removing and installing charge-air cooler.
5. Install rear apron.
-> 635519 Removing and installing rear apron .