For 1990-2009 cars

Cause | Correction
--- | ---
Low oil pressure |

• | Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing .

• | Repair or replace as required.

Loose and/or worn follower, valve rocker arm |

• | Inspect the follower, valve rocker arm.

• | Repair or replace as required.

Improper lubrication to the followers, valve rocker arms | Inspect the following components, and repair or replace as required:

• | The follower, valve rocker arm

• | The SHLA, valve lifter

• | The oil filter bypass valve

• | The oil pump and pump screen

• | The cylinder head oil galleries

• | The engine block oil galleries

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 |

• | Inspect the engine camshaft lobes.

• | 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:

• | 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