These engines are difficult to work on and require special tools for many procedures. On any procedure involving
Timing Chain,
Camshaft, or
Cylinder Head removal, the steps must be read carefully and disassembly must proceed using the special tools; otherwise, damage to the engine could result. Begin by removing the valve cover(s). Due to the interference design of these engines, the rocker arms must be removed before the timing chains and camshafts. Position the pistons off TDC before compressing the valve springs to remove the rocker arms or lash adjusters, compressing one cylinder at a time. Use a valve spring compressor to compress the spring enough to remove the rocker arm, ensuring that rocker arms and lash adjusters are matched to their original locations. Insert a valve spring spacer before compressing to prevent damage to the valve seal. Remove the hydraulic lash adjuster, applying penetrating oil if necessary. For 3-valve 4.6L and 5.4L engines, follow a two-stage process to remove rocker arms, ensuring to rotate the engine appropriately and label all components for reassembly. For the 5.0L engine, remove the camshaft operating the roller followers and separate the hydraulic lash adjusters from their clips. In 6.2L engines, remove the lower eight spark plugs, rotate the crankshaft to open the intake and exhaust valves on designated cylinders, and remove the rocker shaft assemblies. Inspect each adjuster for wear or damage, ensuring the plunger is not stuck, and consider replacing the entire set if any adjusters are replaced. Inspect the rocker arms for wear, particularly at contact points. When installing, bleed air from the lash adjusters, lubricate necessary components, and install them with the valve spring depressed. For 6.2L engines, clean and lubricate rocker arms and shafts before installation, positioning the camshaft lobes correctly for each cylinder during the process. The remainder of installation follows the reverse order of removal.