267619 Removing and installing primary catalytic converter on 4.8-litre V8 DFI engines
WM 267619 Removing and installing primary catalytic converter on 4.8-litre V8 DFI engines
Technical values
Preliminary work
1. Remove engine compartment cover above the oxygen sensor connectors. => 700219 Removing and installing front cover (engine compartment) - section on "Removing"
2. Remove main catalytic converter. => 267319 Removing and installing (main) catalytic converter on 4.8-litre V8 DFI engines - section on "Removing"
Removing primary catalytic converter
Removing primary catalytic converter on cylinder bank 1-4
CAUTION
Hot components
- Risk of burns
-> Let hot components cool down.
-> Wear personal protective gear.
1. Disconnect the oxygen sensor connector for the oxygen sensor behind the catalytic converter at the water splash panel (follow cable routing) and unclip the cables from the holder. => see figure
Oxygen sensor connectors
2. Expose oxygen sensor cable -1- and route it down to the primary catalytic converter.
Catalytic converter on naturally aspirated engine (figure shows cylinders 5 to 8)
3. Remove sheetmetal holders for the primary catalytic converter -7, 8, 10-.
Holder for catalytic converter - naturally aspirated engine
NOTICE
Studs and nuts not loosened correctly
- Threaded bolts can break off exhaust manifold
-> Replace damaged exhaust manifold.
-> Clean the studs and nuts on the exhaust manifold before loosening them and spray with anti-rust agent.
-> Loosen nuts carefully. Loosen the nuts by carefully turning them in both directions if they are very stiff.
-> Heat the threaded joint if necessary.
4. Carefully loosen the flange nuts using a change-over ratchet and several extensions. -2- => Flange bolts securing primary catalytic converter to exhaust manifold
Catalytic converter on naturally aspirated engine (figure shows cylinders 5 to 8)
Flange bolts securing primary catalytic converter to exhaust manifold
NOTICE
Projecting ceramic catalytic converter
- Risk of damage to ceramic catalytic converter
-> Ensure that your work area is well illuminated.
-> Carefully guide the projecting ceramic catalytic converter past the studs on the exhaust manifold.
-> Cover and store the ceramic monolith for the primary catalytic converter in a safe place until you are ready to install it.
-> Protect the ceramic monolith from damage while you are working on the primary catalytic converter. If there are deep cracks or large chips, replace the primary catalytic converter. Slight superficial damage will not impair its function.
5. Carefully remove the primary catalytic converter with the help of another worker.
Ceramic monolith and installation position
6. Remove sheetmetal seal -4-. Clean sealing faces.
Removing primary catalytic converter on cylinder bank 5-8
CAUTION
Hot components
- Risk of burns
-> Let hot components cool down.
-> Wear personal protective gear.
1. Disconnect the oxygen sensor connector for the oxygen sensor behind the catalytic converter at the water splash panel (follow cable routing) and unclip the cables from the holder. => Oxygen sensor connector (figure shows cylinders 1 to 4)
Oxygen sensor connector (figure shows cylinders 1 to 4)
2. Expose oxygen sensor cable -1- and route it down to the primary catalytic converter.
Catalytic converter - naturally aspirated engine
3. Remove heat shield on the cardan joint of the steering column. -arrows-
Heat shield on steering gear
4. Unscrew two coolant pipe screws on the converter bell housing -arrow-. Loosen the coolant pipe.
Coolant pipes on converter bell housing
5. Remove sheetmetal holders for the primary catalytic converter -6, 7, 10-.
Holder for catalytic converter - naturally aspirated engine
NOTICE
Studs and nuts not loosened correctly
- Threaded bolts can break off exhaust manifold
-> Replace damaged exhaust manifold.
-> Clean the studs and nuts on the exhaust manifold before loosening them and spray with anti-rust agent.
-> Loosen nuts carefully. Loosen the nuts by carefully turning them in both directions if they are very stiff.
-> Heat the threaded joint if necessary.
6. Carefully loosen the flange nuts using a change-over ratchet and several extensions. -2- => Flange bolts securing primary catalytic converter to exhaust manifold
Catalytic converter on naturally aspirated engine (figure shows cylinders 5 to 8)
Flange bolts securing primary catalytic converter to exhaust manifold
NOTICE
Projecting ceramic catalytic converter
- Risk of damage to ceramic catalytic converter
-> Ensure that your work area is well illuminated.
-> Carefully guide the projecting ceramic catalytic converter past the studs on the exhaust manifold.
-> Cover and store the ceramic monolith for the primary catalytic converter in a safe place until you are ready to install it.
-> Protect the ceramic monolith from damage while you are working on the primary catalytic converter. If there are deep cracks or large chips, replace the primary catalytic converter. Slight superficial damage will not impair its function.
7. Carefully remove the primary catalytic converter with the help of another worker.
Ceramic monolith and installation position
8. Remove sheetmetal seal -4-. Clean sealing faces.
Installing primary catalytic converter
Installing primary catalytic converter on cylinder bank 1-4
1. Ensure sealing faces of exhaust system are clean.
2. Replace flange gasket -4- and slide it over the studs on the exhaust manifold -5-.
Ceramic monolith and flange gasket
NOTICE
Projecting ceramic catalytic converter
- Risk of damage to ceramic catalytic converter
-> Ensure that your work area is well illuminated.
-> Carefully guide the projecting ceramic catalytic converter past the studs on the exhaust manifold.
-> Cover and store the ceramic monolith for the primary catalytic converter in a safe place until you are ready to install it.
-> Protect the ceramic monolith from damage while you are working on the primary catalytic converter. If there are deep cracks or large chips, replace the primary catalytic converter. Slight superficial damage will not impair its function.
3. Carefully move primary catalytic converter into installation position.
4. Fit new fastening nuts between the exhaust manifold and primary catalytic converter, but leave them loose.
5. Make sure that the sheetmetal holder for the primary catalytic converter fits correctly on the exhaust manifold after you tighten the nuts -8-.
Holder for catalytic converter - naturally aspirated engine
6. Fit fastening screw on catalytic converter holder and nuts to the specified tightening torque and according to the specified tightening sequence => Flange bolts securing primary catalytic converter to exhaust manifold. For details of tightening torque for transmission bolts, see => 373527 Removing and mounting transmission - section on "Mounting"=> Tightening torque: 23 Nm (17 ftlb.) => Tightening torque: 23 Nm (17 ftlb.)
Flange bolts securing primary catalytic converter to exhaust manifold
CAUTION
Danger of fire and material damage.
-> Lay the oxygen sensor cable so that it cannot touch the exhaust manifold.
7. Route oxygen sensor cable and clip into position. -1-
Catalytic converter on naturally aspirated engine (figure shows cylinders 5 to 8)
8. Plug in the connector for the oxygen sensor behind the catalytic converter at the water splash panel.
Installing primary catalytic converter on cylinder bank 5-8
CAUTION
Danger of fire and material damage.
-> Lay the oxygen sensor cable so that it cannot touch the exhaust manifold.
NOTICE
Projecting ceramic catalytic converter
- Risk of damage to ceramic catalytic converter
-> Ensure that your work area is well illuminated.
-> Carefully guide the projecting ceramic catalytic converter past the studs on the exhaust manifold.
-> Cover and store the ceramic monolith for the primary catalytic converter in a safe place until you are ready to install it.
-> Protect the ceramic monolith from damage while you are working on the primary catalytic converter. If there are deep cracks or large chips, replace the primary catalytic converter. Slight superficial damage will not impair its function.
1. Ensure sealing faces of exhaust system are clean.
2. Replace flange gasket -4- and slide it over the studs on the exhaust manifold -5-.
Ceramic monolith and flange gasket
NOTICE
Projecting ceramic catalytic converter
- Risk of damage to ceramic catalytic converter
-> Ensure that your work area is well illuminated.
-> Carefully guide the projecting ceramic catalytic converter past the studs on the exhaust manifold.
-> Cover and store the ceramic monolith for the primary catalytic converter in a safe place until you are ready to install it.
-> Protect the ceramic monolith from damage while you are working on the primary catalytic converter. If there are deep cracks or large chips, replace the primary catalytic converter. Slight superficial damage will not impair its function.
3. Carefully move primary catalytic converter into installation position.
4. Fit new fastening nuts between the exhaust manifold and primary catalytic converter, but leave them loose.
5. Make sure that the sheetmetal holder for the primary catalytic converter fits correctly on the exhaust manifold after you tighten the nuts -8-.
Holder for catalytic converter - naturally aspirated engine
6. Fit fastening screw on catalytic converter holder and nuts to the specified tightening torque and according to the specified tightening sequence => Flange bolts securing primary catalytic converter to exhaust manifold. For details of tightening torque for transmission bolts, see => 373527 Removing and mounting transmission - section on "Mounting"=> Tightening torque: 23 Nm (17 ftlb.) => Tightening torque: 23 Nm (17 ftlb.)
Flange bolts securing primary catalytic converter to exhaust manifold
CAUTION
Danger of fire and material damage.
-> Lay the oxygen sensor cable so that it cannot touch the exhaust manifold.
7. Route oxygen sensor cable and clip into position. -1-
Catalytic converter on naturally aspirated engine (figure shows cylinders 5 to 8)
8. Fit heat shield on the cardan joint of the steering column. -arrows- => Tightening torque: 10 Nm (7.5 ftlb.)
Heat shield on steering gear
9. Fit coolant pipe on converter bell housing -arrow-.
Coolant pipes on converter bell housing
10. Plug in the connector for the oxygen sensor behind the catalytic converter at the water splash panel.
Subsequent work
1. Install main catalytic converter. => 267319 Removing and installing (main) catalytic converter on 4.8-litre V8 DFI engines - section on "Installing"
2. Fit engine compartment cover above the oxygen sensor connectors. => 700219 Removing and installing front cover (engine compartment) - section on "Installing"