When the engine is switched on, oil pressure in the hydraulic lifters changes rapidly, which allows for efficient adjustment. When the engine is running, the constant movement and changing oil pressure can prevent precise lash adjustment.
Therefore, it is preferable to adjust the valve lash on the 5.7L Vortec engine using the traditional technique, which is known as the "cold engine method." This entails adjusting the lash when the engine is off and completely cold. To ensure accurate adjustment, this strategy includes measuring and adjusting the gap between the valve stem and the rocker arm.
