Low oil pressure.

1. Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing.
2. Repair or replace as required.

Loose and/or worn Stationary Hydraulic Lash Adjuster (SHLA), valve rocker arm.

1. Inspect the SHLA, valve rocker arm.
2. Repair or replace as required.

Incorrect lubrication to the SHLAs, 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 sprocket teeth

Replace the timing chain or chains and sprockets.

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

1. Inspect the engine camshaft lobes.
2. Replace the camshaft or camshafts and SHLAs, valve lifters, as required.

Worn valve guides or valve stems

Inspect the following components, and repair as required:

Inspect the following components, and repair as required: