Intake Manifold

Complete removal and replacement of the intake manifold on the 2008 Dodge Viper 8.4L V10, including fuel rail removal, throttle body disconnection, and all associated vacuum and electrical connections.

Warnings

Tools required

Parts

• Intake manifold gasket set × 1 — Use OEM Mopar specification
• Fuel injector O-ring kit × 1 — Use OEM specification if disturbing injectors
• Throttle body gasket × 1 — Use OEM specification

Preparation

1. Ensure engine is completely cold (wait at least 2 hours after last operation)
2. Disconnect negative battery cable and secure away from terminal
3. Remove engine cover by releasing fasteners at front and rear mounting points
4. Remove complete air intake system including airbox, intake tube, and mass airflow sensor assembly
5. Relieve fuel system pressure: remove fuel pump relay from power distribution center, attempt to start engine and let it stall, then crank for 5 seconds to ensure pressure is released
6. Place drain pan and shop towels under fuel rail area to catch residual fuel
7. Document all vacuum line routing with photographs from multiple angles

Procedure

1. 1

   Disconnect throttle body and related components
   Disconnect the electrical connector from the throttle body. Disconnect the electronic throttle control (ETC) connector; this vehicle uses drive-by-wire and has no throttle cable. The electronic throttle body on this engine does not use idle air control coolant hoses; verify no coolant lines are attached before removal. Remove the 4 bolts securing the throttle body to the intake manifold and carefully remove the throttle body, setting it aside without stressing attached hoses.
2. 2

   Disconnect fuel rail and injector connections
   Disconnect the electrical connectors from all 10 fuel injectors by releasing the locking tabs. Using the appropriate fuel line disconnect tool, disconnect the fuel supply line from the fuel rail at the quick-connect fitting. This vehicle uses a returnless fuel system, so there is no return line at the fuel rail to disconnect. Remove the 4 fuel rail mounting bolts securing the fuel rail to the intake manifold. Carefully lift the fuel rail assembly with all injectors attached straight up and out of the manifold, keeping shop towels ready for any residual fuel. Set the fuel rail assembly aside in a clean location.
3. 3

   Disconnect vacuum lines and PCV system
   Working systematically from front to back, disconnect all vacuum lines from the intake manifold including: brake booster vacuum line (large diameter at rear), PCV valve hose, EVAP purge solenoid lines, and any other vacuum-operated accessories. Remove the PCV valve from the valve cover or manifold connection point. Label each connection point if not already documented in photographs.
4. 4

   Disconnect electrical sensors and connectors
   If equipped, disconnect the manifold absolute pressure (MAP) sensor electrical connector and remove the sensor from the manifold; verify sensor presence and location for this engine before removal. Disconnect any intake air temperature sensors. Disconnect knock sensor connectors if they route through the valley area under the manifold. Release any wire harness clips or routing brackets attached to the intake manifold.
5. 5

   Remove accessory brackets and supports
   Remove any accessory mounting brackets that attach to the intake manifold, such as alternator support brackets, A/C line brackets, or wiring harness supports. Check for any coolant crossover tubes or heater hose connections that may pass over or attach to the intake manifold and disconnect as necessary.
6. 6

   Remove intake manifold mounting bolts
   Locate and remove all intake manifold mounting bolts in sequence. The V10 intake manifold is secured by approximately 16-18 bolts around the perimeter and through the valley. Start by loosening bolts in a crisscross pattern from the outer edges working toward the center, then remove completely. Keep bolts organized by location as some may be different lengths. Check for any hidden fasteners beneath wiring harnesses or in the valley area between cylinder banks.
   ⚠Do not pry on manifold sealing surfaces. If manifold is stuck to gasket, gently tap mounting bosses with a soft mallet or use a plastic wedge at non-sealing areas.
7. 7

   Remove intake manifold assembly
   With all fasteners and connections removed, carefully lift the intake manifold straight up and away from the engine. The manifold is large and awkward; use proper lifting technique or have an assistant help. Maneuver the manifold up and out of the engine bay, being careful not to strike surrounding components. Place the manifold on a clean, padded work surface.
8. 8

   Clean gasket surfaces
   Using a plastic gasket scraper, carefully remove all old gasket material from both the intake manifold mating surface and the cylinder head surfaces. Work slowly to avoid gouging the aluminum surfaces. Clean any remaining residue with brake cleaner and lint-free shop towels. Inspect all mating surfaces for warping, cracks, or damage. Ensure the valley area between cylinder banks is clean and free of debris. Use compressed air to blow out any debris from bolt holes.
9. 9

   Inspect and prepare new manifold
   If installing a replacement manifold, transfer all necessary components from the old manifold: fuel rail mounting provisions, sensor ports, vacuum fittings, and any brackets. Inspect new intake manifold gaskets and verify correct positioning and orientation. The gaskets may be multi-piece with separate end seals for the valley area. Apply a small bead of RTV silicone sealant to the corners where end seals meet side gaskets if specified by gasket manufacturer instructions.
10. 10

    Install intake manifold gaskets
    Position the new intake manifold gaskets onto the cylinder head surfaces, ensuring all port openings align correctly. If using individual gaskets per bank, ensure they are correctly oriented left-to-right. Install any valley rail end seals, applying light adhesive or RTV to hold them in position during manifold installation if needed. Verify all gasket alignment tabs are properly seated in their corresponding slots.
11. 11

    Install intake manifold
    Carefully lower the intake manifold into position, aligning it over all gaskets and guiding it straight down without sliding it laterally across the gasket surfaces. Ensure all bolt holes align properly. Start all manifold mounting bolts by hand to ensure proper thread engagement before using any tools. Verify the manifold is seated evenly on all gasket surfaces before proceeding to torque.
12. 12

    Torque intake manifold bolts
    Torque the intake manifold mounting bolts to specification in the proper sequence. Begin with bolts in the center of the manifold and work outward in a crisscross pattern. Perform torquing in multiple stages: first to 50% of final spec, then to 100% of final spec. Make a final pass to verify all bolts are at specification. The typical sequence is center-out, alternating sides to ensure even clamping pressure and prevent gasket distortion.
13. 13

    Reinstall accessory brackets and sensors
    Reinstall all accessory mounting brackets, coolant crossover tubes, and supports removed during disassembly. Install the MAP sensor and any intake air temperature sensors, ensuring seals or O-rings are in good condition. Reconnect all electrical connectors to sensors, ensuring they click and lock securely.
14. 14

    Reinstall fuel rail and injectors
    Inspect all fuel injector O-rings; replace if showing any signs of hardening, cracking, or compression set. Lubricate new O-rings lightly with clean engine oil. Carefully position the fuel rail assembly with injectors over the manifold injector bores, ensuring all 10 injectors align properly. Press the rail assembly down firmly and evenly until all injectors are fully seated. Install the 4 fuel rail mounting bolts and torque to specification. Reconnect fuel supply and return lines, ensuring quick-connect fittings lock completely. Reconnect all 10 injector electrical connectors.
15. 15

    Reconnect vacuum lines and PCV system
    Using photographs and labels as reference, reconnect all vacuum lines to their proper locations: brake booster line, EVAP purge lines, PCV valve, and all accessory vacuum connections. Ensure all hose connections are fully seated and secure. Install PCV valve into its mounting grommet.
16. 16

    Reinstall throttle body
    Install a new throttle body gasket onto the intake manifold mounting surface. Position the throttle body onto the manifold and install the 4 mounting bolts. Torque bolts in a crisscross pattern to specification to ensure even gasket compression. Reconnect the throttle body electrical connector and any coolant hoses. Reinstall throttle cable bracket if equipped.
17. 17

    Final assembly and system checks
    Reinstall the complete air intake system including mass airflow sensor, intake tube, and airbox. Secure all clamps and connections. Reinstall engine cover. Reconnect the negative battery cable. Before starting the engine, turn the ignition to the ON position (without cranking) for 5 seconds, then OFF. Repeat this key-on cycle 3 times to prime the fuel system and check for leaks around fuel rail connections. Inspect carefully for any fuel seepage.

Reassembly

1. Torque specifications are critical for this procedure but not provided in database - follow factory service manual specifications exactly
2. Intake manifold bolt torque sequence must be followed precisely to prevent gasket failure and vacuum leaks
3. All vacuum lines and electrical connections must be restored exactly as documented during disassembly
4. Fuel injector O-rings should be replaced as preventive maintenance whenever fuel rail is removed

Verification

• Start engine and verify it idles smoothly without surging, stalling, or rough running
• Check for vacuum leaks by listening for hissing sounds around manifold perimeter and vacuum line connections
• Verify no fuel odor or visible fuel leaks at fuel rail connections
• Check that all electrical connectors are secure and no warning lights are illuminated on dash
• Verify throttle response is normal and engine accelerates smoothly without hesitation
• Allow engine to reach operating temperature and verify no coolant leaks if coolant system was disturbed
• Road test vehicle and verify normal power delivery and no driveability issues
• Recheck all fuel connections after first drive cycle for any seepage

Related trouble codes on this vehicle

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