See Figure 1
The valves are adjusted with the engine at normal operating temperature (hot). The valve cover and rocker arms will also be hot, and they could burn you if you're not careful.
Inline 6-Cylinder Engines
- Start the engine and allow it to warm to normal operating temperature. Make sure that the engine idles down to normal curb idle speed.
- Turn the engine OFF. Remove the valve cover.
- Using a socket and a breaker bar on the crankshaft bolt, turn the engine in the normal direction of rotation. Locate the #1 cylinder intake rocker arm and watch it's movement as you rotate the engine (the number one cylinder is the front most cylinder). Refer to the illustration for valve identification.
- As the engine rotates, the #1 intake valve will open (compress the valve spring) and then close (uncompress the valve spring). Once the valve has closed, align the mark on the crankshaft pulley to the 0 degree mark on the timing scale. The #1 piston is now at TDC (Top Dead Center).
- The lash is measured between the rocker arm and the tip of the valve. To check the lash, insert the proper size feeler gauge between the rocker arm and the valve tip. A slight drag should be felt. The valve clearances should be:
Intake: 0.012"Exhaust: 0.024"
Intake: 0.010"Exhaust: 0.020"
- If there is no drag, or the feeler gauge won't fit, adjust the clearance by tightening or loosening the adjusting screw on the end of the rocker arm. Once both intake and exhaust valves have been adjusted, rotate the engine 1 / 3 of a revolution (or 120 degrees) and adjust the valves on the next cylinder in the firing order. The firing order is: 1-5-3-6-2-4.
- Repeat step 6 until you have gone through the firing order. Once all the valves have been adjusted, install the valve cover, using a new gasket coated with sealer. Run the engine and check for oil leaks.