Low oil pressure

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

Worn valve rocker arm

Replace the valve rocker arm.

Improper lubrication to the valve rocker arms

Inspect the following components and repair or replace as required:

• The valve rocker arm
• The valve lifter
• The oil filter bypass valve
• The oil pump and pump screen
• The engine block oil galleries

Broken valve spring

Replace the valve spring.

Worn or dirty valve lifters

Replace the valve lifters.

Stretched timing chain and/or damaged sprocket teeth

Replace the timing chain and sprockets.

Worn, damaged, or faulty timing chain tensioner

Replace the tensioner.

Worn engine camshaft lobes

• Inspect the engine camshaft lobes.
• Replace the camshaft and valve lifters as required.

Worn valve guides or valve stems

Inspect the following components, and repair as required:

• The valves
• The valve guides

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:

• The valves
• The valve guides