Exhaust Manifold: Service and Repair
WM 261019 Removing and installing exhaust manifold - Turbo
Technical values
Preliminary work
1. Preliminary work for cylinder bank 4-6:
1.1. Remove rear apron.
=> 635519 Removing and installing rear apron.
1.2. Remove charge-air cooler.
=> 214319 Removing and installing charge-air cooler.
1.3. Remove heat shield on catalytic converter (cylinder bank 1-3).
=> 635019 Removing and installing rear bumper.
2. Preliminary work for cylinder bank 1-3:
2.1. Remove tailpipe cover.
=> 263519 Removing and installing tailpipe cover - Turbo.
Removing exhaust manifold
Removing exhaust manifold - 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)
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.
1. Loosen and screw off three M8 hexagon nuts (a/f 13) on the exhaust manifold flange for the turbocharger -arrows-.
1.1. Replace hexagon nuts.
Exhaust manifold flange on cylinder bank 1-3
2. Unscrew nine external Torx screws (E12, M8 x 27) -arrows- on the exhaust manifold.
2.1. Replace screws.
Exhaust manifold threaded joint
3. Press the turbocharger up slightly and pull the exhaust manifold off the threaded bolts on the turbocharger.
3.1. Replace metal seals.
Removing exhaust manifold - 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. Loosen the turbocharger holder -arrow-.
Holder for turbocharger for cylinder bank 4-6
1.1. Loosen external Torx screw (E12, M8 x 16) on the holder through the opening in the tailpipe cover => Holder for turbocharger 4-6 accessible through tailpipe opening.
Holder for turbocharger 4-6 accessible through tailpipe opening
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.
2. Loosen and screw off three M8 hexagon nuts (a/f 13) on the exhaust manifold flange for the turbocharger -arrows-.
2.1. Replace hexagon nuts.
Exhaust manifold flange on cylinder bank 4-6
3. Unscrew nine external Torx screws (E12, M8 x 27) -arrows- on the exhaust manifold.
3.1. Replace screws.
Exhaust manifold threaded joint
4. Press the turbocharger out slightly and pull the exhaust manifold off the studs on the turbocharger.
4.1. Replace metal seals.
Installing exhaust manifold
Installing exhaust manifold - cylinder bank 1-3
Information
- Always replace seals.
1. Slide a new metal seal onto the threaded bolts on the turbocharger.
2. Fit exhaust manifold with new external Torx screws and hexagon nuts.
2.1. Fit a new metal seal on the sealing face of the exhaust manifold.
2.2. Press the turbocharger up slightly and slide the exhaust manifold flange onto the studs on the turbocharger.
2.3. Pre-position the exhaust manifold with two new external Torx screws (E12, M8 x 27).
2.4. Fit the other seven new screws. => Exhaust manifold threaded joint
Exhaust manifold threaded joint
2.5. Fit three new M8 hexagon nuts (a/f 13) on the three-hole flange.
3. Fit and tighten new external Torx screws (E12, M8 x 27) on the exhaust manifold uniformly from the inside out.
Observe tightening sequence -1 to 9- and tightening specifications!
Tightening specifications for exhaust manifold with catalytic converter
3.1. Initial tightening:
=> Initial tightening: 15 Nm (11 ftlb.)
3.2. Final tightening torque angle:
=> Torque angle: 25°
4. Tighten three M8 hexagon nuts (a/f 13) on the turbocharger flange for the exhaust manifold -arrows-.
=> Tightening torque: 25 Nm (19 ftlb.)
Exhaust manifold flange on cylinder bank 1-3
Installing exhaust manifold - cylinder bank 4-6
Information
- Always replace seals.
1. Slide a new metal seal onto the studs on the turbocharger.
2. Fit exhaust manifold with new external Torx screws and hexagon nuts.
2.1. Fit a new metal seal on the sealing face of the exhaust manifold.
2.2. Press the turbocharger out slightly and slide the three-hole flange onto the studs on the turbocharger.
2.3. Pre-position the exhaust manifold on the cylinder head with two new external Torx screws (E12, M8 x 27).
2.4. Fit the other seven new screws on the cylinder head. => Exhaust manifold threaded joint
Exhaust manifold threaded joint
2.5. Fit three new M8 hexagon nuts (a/f 13) on the three-hole flange.
3. Fit and tighten external Torx screws on the exhaust manifold uniformly from the inside out.
Observe tightening sequence and specifications as for cylinder bank 1-3!
Tightening specifications for exhaust manifold with catalytic converter
4. Tighten three M8 hexagon nuts (a/f 13) on the turbocharger flange for the exhaust manifold -arrows-.
Tightening torque as for cylinder bank 1-3!
Exhaust manifold flange on cylinder bank 4-6
5. Tighten external Torx screw (E12, M8 x 16) on the turbocharger holder => Holder for turbocharger 4-6 accessible through tailpipe opening.
=> Tightening torque: 23 Nm (17 ftlb.)
Holder for turbocharger 4-6 accessible through tailpipe opening
Subsequent work
1. Subsequent work for cylinder bank 1-3:
1.1. Install heat shield on catalytic converter (cylinder bank 1-3).
=> 635019 Removing and installing rear bumper.
1.2. Install charge-air cooler.
=> 214319 Removing and installing charge-air cooler.
1.3. Install rear apron.
=> 635519 Removing and installing rear apron.
2. Subsequent work for cylinder bank 4-6:
2.1. Install tailpipe cover on cylinder bank 4-6.
=> 263519 Removing and installing tailpipe cover - Turbo.