Valve Train Diagnosis

Inspect the following areas:
^ Inspect the valve lifter and valve stem tip mating surfaces. These surfaces should be smooth and free of scoring or other damage.
^ Inspect the valve lifters for scoring where it contacts the camshaft.
^ Inspect the camshaft journals, lobes, and camshaft housing bores for wear or scoring.
^ Timing chain for teeth that are no longer concentric
^ The camshaft gears and mating surfaces for damage or signs of movement
^ The key and crankshaft keyway for wear
^ The timing chain for binding or excessive wear