Upper Engine Noise, Regardless of Engine Speed

Engine Mechanical - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5133057

	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 belt and/or damaged sprocket teeth	Replace the timing belt and sprockets.
	Worn, damaged, or faulty timing belt tensioners	Replace the 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
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Cause	Correction
	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