Valve Adjustment

This procedure guides you through adjusting valve lash on the 2008 Dodge Viper 8.4L V10 engine, ensuring proper valve train clearances for optimal performance and longevity.

Warnings

Tools required

Parts

• Valve cover gasket set (both banks) × 1 — Use OEM specification
• Valve cover bolt grommets/seals × 1 — Use OEM specification
• Spark plug tube seals (if damaged) × 10 — Use OEM specification

Preparation

1. Ensure engine is completely cold (preferably overnight cold soak).
2. Disconnect negative battery terminal to prevent accidental starter engagement.
3. Remove engine cover by pulling upward on the front clips and lifting off.
4. Label and disconnect any vacuum lines, breather hoses, or wiring harnesses that interfere with valve cover removal.
5. Have a clean workspace prepared for organizing valve cover bolts and components by bank.

Procedure

1. 1

   Remove left bank (driver side) valve cover
   Remove the ignition coils from the left bank by disconnecting the electrical connectors and removing the mounting bolts. Remove the valve cover bolts in a crisscross pattern working from the outside inward. There are 10 bolts securing each valve cover. Carefully lift the valve cover straight up to avoid damaging spark plug tube seals. Inspect the gasket and tube seals for damage.
2. 2

   Remove right bank (passenger side) valve cover
   Repeat the process for the right bank valve cover. Remove ignition coils, disconnect any interfering components, and remove the 10 valve cover bolts in a crisscross pattern. Lift the valve cover carefully and inspect seals and gaskets.
3. 3

   Rotate engine to TDC for cylinder 1
   Using the correct socket on the crankshaft bolt (verify size against factory service manual), rotate the engine clockwise (viewed from front) until cylinder 1 is at top dead center on the compression stroke. Both intake and exhaust valves for cylinder 1 should be closed (rocker arms loose). Verify by checking that the timing marks align and that you can move both rocker arms for cylinder 1 with light finger pressure, indicating they are on the base circle of the cam.
4. 4

   Establish valve adjustment firing order sequence
   The Viper V10 firing order is 1-10-9-4-3-6-5-8-7-2. VERIFY cylinder bank assignments against factory service manual before proceeding. Cylinder numbering and bank assignment must be confirmed against the factory service manual. Adjust valves using the manufacturer-specified two-step method, verifying each cylinder is on the base circle of the cam (both rocker arms loose) before adjusting, rather than relying on a fixed cylinder grouping.
5. 5

   Adjust valves for first position (cylinder 1 at TDC)
   With cylinder 1 at TDC compression stroke, adjust the following cylinders: 1, 3, 4, 5, 8, and 10. For each cylinder, loosen the rocker arm adjusting nut while holding the pushrod with your fingers to prevent it from spinning. STOP: The 8.4L Viper V10 uses hydraulic roller lifters with non-adjustable rocker arms. There is no feeler-gauge valve lash adjustment for this engine. Confirm the correct maintenance procedure (rocker arm torque spec, lifter/pushrod inspection) against the factory service manual before proceeding. locknut torque.
6. 6

   Rotate crankshaft 360 degrees
   Rotate the crankshaft clockwise exactly 360 degrees (one full rotation). Cylinder 1 will now be at TDC on the exhaust stroke. Verify proper position by confirming which cylinders now have both rocker arms on the base circle (loose) before making any adjustments.
7. 7

   Adjust valves for second position
   With the crankshaft rotated 360 degrees from the first position, adjust the remaining cylinders: 2, 6, 7, and 9. Use the same adjustment procedure as in step 5, using 0.012 inches for intake valves and 0.016 inches for exhaust valves. Loosen the adjusting nut, insert the feeler gauge, tighten until proper drag is achieved, and secure the locknut.
8. 8

   Verify all adjustments
   Rotate the engine by hand through two complete revolutions and recheck several valve lash measurements randomly across both banks to confirm adjustments have not changed. If any valve lash has changed significantly, re-adjust that valve and verify the locknut was properly torqued.
9. 9

   Clean valve cover mating surfaces
   Using a plastic gasket scraper, carefully clean all old gasket material from both valve cover mating surfaces and cylinder head surfaces. Do not gouge or scratch the aluminum surfaces. Wipe clean with shop towels and ensure no debris falls into the engine.
10. 10

    Install new valve cover gaskets and reinstall covers
    Install new valve cover gaskets onto the valve covers, ensuring they seat properly in the grooves. Replace spark plug tube seals if they show any signs of deterioration. Apply a small dab of RTV sealant at the cam cap corners where the gasket meets the head if specified by the gasket manufacturer. Install each valve cover, starting bolts by hand to ensure proper alignment. Tighten the valve cover bolts (quantity per factory service manual) in a crisscross pattern from center outward, working in multiple passes to the factory-specified final torque. Reinstall ignition coils with their mounting bolts torqued properly.
11. 11

    Reconnect components and test
    Reconnect all vacuum lines, breather hoses, and wiring harnesses that were removed. Reconnect the negative battery terminal. Reinstall the engine cover. Start the engine and listen for any unusual valve train noise. Allow the engine to reach operating temperature and inspect both valve covers for oil leaks. A slight seep that stops after the gaskets compress is normal, but active dripping indicates improper installation.

Reassembly

1. Tighten valve cover bolts in multiple passes using a crisscross pattern to avoid warping the covers.
2. Ensure all ignition coil connectors are fully seated and locked.
3. Double-check that all vacuum lines and breather hoses are properly reconnected.
4. Verify the engine cover clips are fully engaged before starting the vehicle.

Verification

• Start the engine and listen for proper valve train operation - no excessive ticking or tapping sounds.
• Check for oil leaks around both valve covers after reaching operating temperature.
• Test drive the vehicle and verify smooth operation across the RPM range.
• After the first heat cycle, recheck valve cover bolt torque and inspect for any oil seepage.

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