Cause
| Correction
|
Low oil pressure
|
| • | Repair or replace as required. |
|
Loose and/or worn valve rocker arm attachments
|
| • | Inspect the valve rocker arm, bolt, and pedestal. |
| • | Repair or replace as required. |
|
Worn or damaged valve rocker arm
|
| • | Inspect the rocker arm for wear or missing needle bearings |
| • | Replace the valve rocker arms as required. |
|
Bent or damaged pushrod
| Inspect the following components and replace as required:
Inspect the top of the pistons for valve contact. If the top of the piston shows valve contact, replace the piston and pin assembly.
|
Improper lubrication to the valve rocker arms
| Inspect the following components and repair or replace as required:
| • | The oil filter bypass valve |
| • | The oil pump and pump screen |
| • | Improper operation of the displacement-on-demand (DoD) oil pressure relief valve |
| • | The engine block oil galleries |
|
Broken valve spring
| Replace the valve spring and spring shim.
|
Worn or dirty valve lifters
| Replace the valve lifters.
|
Stretched or broken timing chain and/or damaged sprocket teeth
| Replace the timing chain and sprockets.
|
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:
|
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:
|
Cut or damaged oil pump screen O-ring seal, which may cause aeration of the engine oil
| Repair as required. Refer to
Oil Pressure Diagnosis and Testing
.
|
