Unlock the power of your 5.9l cummins: a comprehensive tutorial on checking valve lash

Maintaining a healthy and well-running 5.9 Cummins engine requires regular checks and adjustments, including checking valve lash. Valve lash refers to the clearance between the rocker arm and the valve stem, and it is crucial for ensuring proper engine operation. This comprehensive guide will provide you with step-by-step instructions on how to check valve lash on a 5.9 Cummins engine, empowering you to perform this essential maintenance task with confidence.

Understanding Valve Lash

Valve lash is the gap between the valve stem and the rocker arm when the valve is closed. This clearance allows the valve to open and close freely without binding or sticking. Proper valve lash is essential for efficient engine operation, as it ensures that the valves open and close at the correct time, maximizing power and fuel efficiency while minimizing emissions.

Tools and Materials Required

Before beginning, gather the following tools and materials:

• Feeler gauge
• 10mm wrench
• 15mm wrench
• 3/8-inch drive ratchet
• 3/8-inch extension
• 10mm socket
• 15mm socket
• Clean rags or paper towels

Safety Precautions

• Ensure the engine is cool to the touch before starting work.
• Wear appropriate safety gear, including gloves and eye protection.
• Disconnect the negative terminal of the battery to prevent electrical hazards.

Step-by-Step Instructions

1. Locate the Valve Cover

Identify the valve cover on the engine. It is typically located at the top of the engine and has a large rectangular shape.

2. Remove the Valve Cover

Using a 10mm wrench, loosen the bolts securing the valve cover. Carefully remove the valve cover and set it aside.

3. Identify the Rocker Arms

Inside the valve cover, you will see the rocker arms. These are the components that contact the valve stems and open and close the valves.

4. Locate the Adjustment Screws

On each rocker arm, there is an adjustment screw. This screw is used to adjust the valve lash.

5. Measure the Valve Lash

Using a feeler gauge, measure the clearance between the rocker arm and the valve stem. The correct valve lash for a 5.9 Cummins engine is typically between 0.006 and 0.010 inches.

6. Adjust the Valve Lash

If the valve lash is not within the specified range, use a 15mm wrench to loosen the locknut on the adjustment screw. Turn the adjustment screw in or out to achieve the correct valve lash.

7. Tighten the Locknut

Once the correct valve lash is achieved, tighten the locknut using a 15mm wrench.

8. Reinstall the Valve Cover

Place the valve cover back on the engine and tighten the bolts using a 10mm wrench.

9. Reconnect the Battery

Reconnect the negative terminal of the battery.

Tips for Success

• Check valve lash regularly, as it can change over time due to engine wear.
• Always refer to the manufacturer’s specifications for the correct valve lash settings.
• If you are not comfortable adjusting valve lash yourself, seek assistance from a qualified mechanic.
• Keep a record of your valve lash adjustments for future reference.

Troubleshooting Common Issues

• Engine misfiring: Incorrect valve lash can cause engine misfiring due to improper valve timing.
• Reduced engine power: Insufficient valve lash can prevent the valves from opening fully, reducing engine power.
• Excessive valve noise: Too much valve lash can create excessive noise due to the rocker arms contacting the valve stems excessively.

Takeaways: Empowering You to Maintain Your 5.9 Cummins

By following these step-by-step instructions, you can confidently check valve lash on your 5.9 Cummins engine, ensuring optimal performance and longevity. Remember, regular maintenance is key to keeping your engine running smoothly and efficiently.

Information You Need to Know

Q: How often should I check valve lash on my 5.9 Cummins?

A: It is recommended to check valve lash every 15,000 to 30,000 miles, or as per the manufacturer’s specifications.

Q: What are the symptoms of incorrect valve lash?

A: Incorrect valve lash can cause engine misfiring, reduced engine power, and excessive valve noise.

Q: Can I adjust valve lash myself if I am not a mechanic?

A: While it is possible to adjust valve lash yourself, it is recommended to seek assistance from a qualified mechanic if you are not comfortable performing this task.