Low oil pressure

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

Worn camshafts and/or valve rocker arms or improperly adjusted rocker arms

Adjust rocker arms or replace components, as required.

Improper lubrication to the valve rocker arms

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

•	The valve rocker arm and shaft

•	The oil filter

•	The oil filter bypass valve

•	The oil pump and pump screen

•	The cylinder head oil galleries

•	The engine block oil galleries and restrictors

2. Inspect the intake rocker arm control system for proper operation.

Broken valve spring

Replace the valve spring.

Stretched or broken timing components

Replace the timing components.

Worn timing belt or tensioner

Replace the timing belt tensioner, as required.

Worn timing belt

Replace the timing belt, as required.

Worn camshaft lobes

1. Inspect the camshaft lobes.
2. Replace the camshafts, as required.

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: