Valve Adjustment

This procedure adjusts valve lash on the 2005 Dodge Viper 8.3L V10 engine by removing valve covers, measuring clearances with feeler gauges, and adjusting rocker arm screws to factory specifications.

Warnings

Tools required

Parts

• Valve cover gaskets (left and right) × 2 — Use OEM specification
• Valve cover bolt grommets/seals × 1 — Use OEM specification
• Spark plug tube seals × 10 — Use OEM specification
• Intake plenum gaskets × 1 — Use OEM specification

Preparation

1. Ensure engine is completely cold (ambient temperature)
2. Park vehicle on level surface and engage parking brake
3. Disconnect negative battery cable
4. Remove engine cover if equipped
5. Label and photograph all electrical connections and vacuum lines before disconnection

Procedure

1. 1

   Remove intake plenum assembly
   Disconnect throttle body electrical connector and all vacuum lines from the intake plenum. Remove the air intake tube from the throttle body. Disconnect any PCV hoses or breather tubes connected to the valve covers. Remove the 10 intake plenum mounting bolts securing the plenum to the intake manifold. Carefully lift the plenum assembly off the engine and set aside. Remove and discard the plenum gaskets.
2. 2

   Remove ignition coils and spark plugs
   Disconnect all 10 ignition coil electrical connectors. Remove the coil mounting bolts (one per coil) and lift each coil pack out of the valve cover. Using a spark plug socket, remove all 10 spark plugs and set them aside in order. This provides access to the valve covers and allows easier engine rotation.
3. 3

   Remove valve covers
   Remove the valve cover bolts from both left and right valve covers. Each valve cover is secured by 8 bolts. Carefully lift the valve covers off, breaking the gasket seal if necessary with a plastic scraper or pry bar. Do not pry against the gasket sealing surface. Remove and discard the old valve cover gaskets and spark plug tube seals.
4. 4

   Rotate engine to TDC cylinder 1
   Using a socket on the crankshaft pulley bolt, rotate the engine clockwise until the timing mark on the crankshaft damper aligns with the TDC (0 degree) mark on the timing cover. Verify cylinder 1 is at TDC compression stroke by ensuring both intake and exhaust valves for cylinder 1 are closed (rocker arms should have lash/movement). If valves are tight, rotate engine one additional full revolution (360 degrees).
   ⚠Always rotate engine in the normal direction of rotation (clockwise from front). Never rotate backwards.
5. 5

   Measure and record valve lash - cylinders 1, 3, 5, 7, 9
   With cylinder 1 at TDC compression, measure valve lash on cylinders 1, 3, 5, 7, and 9. Insert the appropriate feeler gauge between the rocker arm tip and valve stem. Factory specification is 0.012 inch (0.30mm) intake and 0.016 inch (0.41mm) exhaust when cold. Record all measurements. The gauge should slide with light drag; if too loose or too tight, adjustment is needed. Identify intake vs exhaust by tracing the pushrod down to the camshaft - intake valves are on the inside (valley side), exhaust valves are on the outside (manifold side).
6. 6

   Adjust valves requiring correction - cylinders 1, 3, 5, 7, 9
   For each valve requiring adjustment, loosen the rocker arm adjusting screw lock nut while holding the adjusting screw stationary with a screwdriver. Turn the adjusting screw clockwise to decrease lash or counterclockwise to increase lash. Once the correct feeler gauge slides with proper drag, hold the adjusting screw stationary and tighten the lock nut to specification. Re-check the lash after tightening the lock nut to ensure it did not change. Repeat for all valves needing adjustment on these cylinders.
   ⚠Always hold the adjusting screw stationary when tightening the lock nut to prevent changing the adjustment.
   Torque spec

   Valve Lash Adjusting Screw Lock Nut20 Nm (15 lb-ft)
7. 7

   Rotate engine 360 degrees to TDC cylinder 6
   Rotate the crankshaft clockwise exactly one full revolution (360 degrees) until the timing mark returns to TDC. At this position, cylinder 6 will be at TDC compression stroke. Verify by checking that both valves on cylinder 6 have lash.
8. 8

   Measure and record valve lash - cylinders 2, 4, 6, 8, 10
   With cylinder 6 at TDC compression, measure valve lash on cylinders 2, 4, 6, 8, and 10. Use the same feeler gauge technique as before: 0.012 inch intake and 0.016 inch exhaust. Record all measurements for these remaining cylinders.
9. 9

   Adjust valves requiring correction - cylinders 2, 4, 6, 8, 10
   Adjust all valves on these cylinders that are out of specification using the same procedure as step 6. Loosen lock nut, adjust screw to achieve proper lash, hold screw and tighten lock nut to specification, then verify lash did not change. Complete all adjustments before proceeding.
   Torque spec

   Valve Lash Adjusting Screw Lock Nut20 Nm (15 lb-ft)
10. 10

    Verify all adjustments
    Rotate the engine through two complete revolutions and re-check lash on any valves that were adjusted. This ensures lock nuts are properly torqued and adjustments are holding. Make any necessary corrections before reassembly.
11. 11

    Clean and prepare valve cover surfaces
    Thoroughly clean all gasket surfaces on both valve covers and cylinder heads using a plastic scraper. Remove all old gasket material and oil residue. Wipe surfaces clean with shop rags. Inspect valve cover sealing surfaces for warpage or damage. Install new spark plug tube seals into the cylinder heads, ensuring they are fully seated.
12. 12

    Install valve covers
    Install new valve cover gaskets onto the valve covers or cylinder head surfaces per gasket manufacturer instructions. Position each valve cover carefully over the spark plug tubes and onto the cylinder head. Install new valve cover bolt grommets/seals if equipped. Install all valve cover bolts finger-tight, then tighten in a spiral pattern from center outward to specification.
    ⚠Follow specified tightening sequence to prevent valve cover warpage and oil leaks.
    Torque spec

    Valve Cover Bolts10 Nm (7 lb-ft)
13. 13

    Install spark plugs and ignition coils
    Install all 10 spark plugs in their correct positions, tightening to factory specification for aluminum heads (verify exact value in the service manual, typically around 13 lb-ft / 18 Nm; do not overtighten in the aluminum cylinder heads). Install each ignition coil pack into its corresponding valve cover opening, ensuring proper seating. Install coil mounting bolts and tighten. Reconnect all 10 ignition coil electrical connectors.
14. 14

    Reinstall intake plenum
    Install new intake plenum gaskets onto the intake manifold. Position the intake plenum assembly onto the manifold, ensuring all gaskets remain properly aligned. Install all 10 plenum mounting bolts finger-tight, then tighten in a crossing pattern from center outward to specification. Reconnect all vacuum lines, PCV hoses, breather tubes, throttle body electrical connector, and air intake tube.
15. 15

    Final checks and test
    Double-check that all electrical connectors are secure and all vacuum lines are properly connected. Reinstall engine cover if equipped. Reconnect negative battery cable. Start engine and listen for abnormal valve train noise. Engine may run slightly rough for the first few seconds as the fuel system reprimes. Check for oil leaks around valve covers. Allow engine to reach operating temperature and verify smooth operation. Monitor for check engine lights or fault codes.

Reassembly

1. Tighten all fasteners to specified torque values using proper sequence
2. Ensure all electrical connectors are fully seated and locked
3. Verify all vacuum lines are connected to their original locations using reference photos
4. Check that no tools or rags were left in the engine bay

Verification

• Start engine and listen for proper valve train operation - no clicking, tapping, or abnormal noise
• Check for oil leaks around valve cover gaskets after engine reaches operating temperature
• Verify smooth idle and throttle response
• Take vehicle for test drive and confirm normal engine performance under load
• Re-check valve cover area for leaks after 100-200 miles of operation

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