Low oil pressure

Loose and/or worn follower, valve rocker arm

Improper lubrication to the followers, valve rocker arms

Inspect the following components, and repair or replace as required:

Broken valve spring

Replace the valve spring.

Worn or dirty SHLAs, valve lifters

Replace the SHLAs, valve lifters.

Stretched or broken timing chain or chains and/or damaged camshaft position actuator sprocket teeth

Replace the primary timing chain, secondary timing chains, intermediate sprocket, camshaft position actuators and/or related timing components as required.

Worn timing chain tensioner or tensioners

Replace the timing chain tensioner or tensioners as required.

Worn timing chain shoe or shoes

Replace the timing chain shoe or shoes as required.

Worn timing chain guide or guides

Replace the timing chain guide or guides as required.

Worn engine camshaft lobes

Worn valve guides or valve stems

Inspect the following components, and repair as required:

Stuck Valves

Carbon on the valve stem or valve seat may cause the valve to stay open

Inspect the following components, and repair as required: