1. Gather the Necessary Tools:
- Socket wrench
- Breaker bar
- Torque wrench
- Feeler gauge
- Screwdriver or small pry bar
- Clean rag or paper towels
2. Prepare the Engine:
- Allow the engine to cool completely to avoid burns.
- Remove any components that obstruct access to the valve covers, such as the air filter assembly.
3. Remove the Valve Covers:
- Locate the valve covers on top of the engine.
- Use the socket wrench to loosen and remove the bolts or screws that hold the valve covers in place.
- Gently lift off the valve covers, taking care not to spill any oil that might be present.
4. Locate the Valves:
- Each cylinder has two valves: one intake valve and one exhaust valve.
- The valves are located in pairs and are identified by the presence of a rocker arm and valve spring on each valve stem.
5. Check the Valve Lash:
- Insert the feeler gauge between the valve stem and the rocker arm.
- The gap should be within the specified range provided in the vehicle's service manual (typically around 0.005 to 0.015 inches).
6. Adjust the Valve Lash:
- If the valve lash is incorrect, use the pry bar or small screwdriver to turn the adjusting nut on the rocker arm.
- Adjust the nut until the feeler gauge can slide in with a slight drag. Be cautious not to overtighten the nut.
7. Repeat for Other Valves:
- Repeat the process of checking and adjusting the valve lash for all the valves in the engine.
- Work systematically to ensure that you cover all the valves.
8. Reinstall the Valve Covers:
- Once all the valve adjustments are complete, replace the valve covers and gently tighten the bolts or screws to secure them in place.
9. Reinstall Removed Components:
- Reinstall any components that were removed during the process, such as the air filter assembly.
10. Start the Engine and Check:
- Start the engine and let it run for a few minutes.
- Listen for any unusual noises that may indicate incorrect valve adjustments.
- If everything sounds normal, test drive the vehicle to verify smooth engine operation.
Adjusting valve lash on a Chevy 4.3 V6 requires precision and attention to detail. If you are unsure or uncomfortable performing this task, it's best to consult with a qualified mechanic.
