Section 7.4 Three-Piece Exhaust Manifold With Heat Shield

Section 7.4
Three-Piece Exhaust Manifold With Heat Shield

A three-piece, cast-iron exhaust manifold with heat shield is attached to the cylinder head with twelve special alloy hardened bolts. The manifold has a square outlet flange which is bolted directly to the turbocharger turbine housing. Three identical exhaust manifold gaskets are used between the manifold and the cylinder head.‪

Natural gas engine exhaust manifold has a heat shielded exhaust manifold. The insulation wrap provides containment of exhaust heat resulting in increased engine efficiency. See Figure "Typical Exhaust Manifold with Heat Shield" .‪

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 1. Exhaust Manifold with Heat Shield‪

 2. Metallic Heat Shield‪

Figure 1. Typical Exhaust Manifold with Heat Shield

Section 7.4.1
Repair or Replacement of Three-Piece Exhaust Manifold with Heat Shield

To determine if repair is possible or replacement is necessary, perform the following procedure. See Figure "Flowchart for Repair or Replacement of Three-Piece Exhaust Manifold with Heat Shield" .‪

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Figure 2. Flowchart for Repair or Replacement of Three-Piece Exhaust Manifold with Heat Shield

Section 7.4.2
Removal of Three-Piece Exhaust Manifold with Heat Shield

Perform the following steps to remove the exhaust manifold.‪

Note: The exhaust manifold need not be clean prior to removal.

  1. Remove the turbocharger assembly. Refer to "6.5.7 Installation of Turbocharger" .
  2. Remove the bolts that secure the exhaust manifold and exhaust heat shield to the cylinder head.
  3. Remove the heat shields.
  4. Remove the three-piece manifold as an assembly and discard the three exhaust gaskets.

Note: The exhaust manifold should not be cleaned prior to inspection.

Section 7.4.3
Inspection of Three-Piece Exhaust Manifold with Heat Shield

Perform the following steps to inspect the three-piece exhaust manifold.‪

  1. Visually inspect the exhaust manifold sections and heat shield insulation for cracks. If any exhaust manifold sections or heat insulation have cracks, replace individual sections if necessary. If exhaust manifold sections are not damaged, reuse the components.
  2. Check bolts Number 1 and 3 for stress and excessive stretching. Replace bolts if necessary. See Figure "Location of Stressed Bolt and Bolt Torque Sequence" for the location of the bolts.
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    Numbers indicate bolt locations.

    Figure 3. Location of Stressed Bolt and Bolt Torque Sequence

  3. Inspect the remaining exhaust manifold bolts for damage. Replace bolts if necessary.
  4. Inspect exhaust pipe hangers for cracks. Replace components as required. Refer to OEM guidelines for proper replacement procedure.
  5. Inspect the flexible exhaust connection to ensure there is adequate flexibility to permit engine movement without stressing the turbocharger and exhaust manifold. Refer to OEM guidelines for proper flexibility specifications.
  6. Ensure the exhaust pipe is adequately supported. Refer to OEM guidelines to verify that the exhaust pipe is adequately supported.

Section 7.4.4
Installation of Three-Piece Exhaust Manifold with Heat Shield

Perform the following steps to install the exhaust manifold.‪

  1. If disassembled, assemble the three pieces of the exhaust manifold.
  2. Install four exhaust manifold guide studs, (J–36107) into the cylinder head to hold the three exhaust manifold gaskets in the correct position, and facilitate manifold installation. For the modified bolt boss on the reusable center section, include one P/N: 23511667 exhaust manifold spacer under the bolts.

    Note: The bolt tightening pattern on cylinders 1, 2, and 3 reverses between middle-mount and high-mount exhaust manifolds. The exhaust gasket can be positioned either way. Ensure the guide studs and gaskets are positioned correctly for the manifold being installed.

  3. Install the exhaust gaskets to the guide studs.
  4. Install the assembled manifold to the guide studs.
  5. Remove the four guide studs one at a time and install a bolt and spacer to secure the exhaust manifold to the cylinder head. Finger-tighten the bolts.
  6. Install the remaining four bolts and spacers to the holes from which the studs were removed.
  7. Remove the necessary bolts to install the exhaust heat shield.
  8. Torque the bolts to 58-73 N·m (43-54 lb·ft) using the tightening sequence. See Figure "Location of Stressed Bolt and Bolt Torque Sequence" .
  9. Install the turbocharger. Refer to "6.5.7 Installation of Turbocharger" .
  10. Install any other equipment that was removed for this procedure.
    warning

    EXPLOSION

    To avoid injury from an explosion of natural gas, the following precautions must be taken:‪

    • Do not smoke when installing or servicing the engine or fuel system.
    • Installation or servicing of natural gas equipment must only be conducted in well ventilated, natural gas-compatible areas. Do not install or service equipment in an enclosed area where ignition sources are present without first ensuring that an undetected gas leak may be safely vented without being ignited.
    • Natural gas fuel systems are pressurized. Relieve pressure from any fuel system component prior to installation or service of that component. Bleed natural gas lines before installing or servicing any component connected to the fuel lines.
    warning

    EXPLOSION

    To avoid injury from an explosion of natural gas, the following precautions must be taken:‪

    • Use a combustible-gas detector. Liquefied natural gas (LNG) is odorless and cannot be detected by smell. Compressed Natural gas (CNG) may be odorless and may not be detected by smell.
    • Equipment fuel systems are the responsibility of the Original Equipment Manufacturer (OEM). Equipment fuel system guidelines must be closely adhered to when installing or servicing equipment. Refer to OEM guidelines specifying which maintenance procedures require venting of fuel lines and fuel tanks.
    • LNG systems are pressurized and contain extremely cold (-162° C [-260° F]) fluids. Contact the fuel supplier or OEM for LNG safety requirements. Contact with LNG may cause personal injury (freezing).
    • Vent systems on the equipment should be ducted to a safe area whenever equipment is in an enclosed area.
    warning

    PERSONAL INJURY

    To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.‪

  11. Start the engine and check for exhaust leaks.
  12. If exhaust leaks are detected, contact the Detroit Diesel Customer Support Center for further information (313–592–5800).


Series 60 Service Manual - 6SE483
Generated on 10-13-2008

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