| 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 valve rocker arm attachments | Inspect the valve rocker arm stud, nut, or bolt. Repair or replace as required. |
| Worn valve rocker arm | Replace the valve rocker arm. |
| Bent or damaged push rod | Inspect the following components, and replace as required: The valve rocker arm The valve push rod The valve lifter |
| Improper lubrication to the valve rocker arms | Inspect the following components, and repair or replace as required: The valve rocker arm The valve push rod 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 and/or damaged valve rotators | Replace the valve rotators as required. |
| 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 timing chain tensioner if applicable | Replace the timing chain tensioners as required. |
| Worn engine camshaft lobes | Inspect the engine camshaft lobes. Replace the camshaft and valve lifters as required. |
| Damaged, broken, or dirty, balance shaft sprocket teeth if applicable | Inspect the following components, and repair as required: The balance shaft gear The camshaft gear The balance shaft rear bushing |
| 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 |
Upper Engine Noise, Regardless of Engine Speed