Upper Engine Noise, Regardless of Engine Speed
| 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. |
| 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 or broken timing chain and/or damaged sprocket teeth | Replace the timing chain and sprockets. |
| Worn, damaged, or faulty timing chain tensioners | Replace the timing chain tensioners. |
| 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 |
