Upper Engine Noise, Regardless of Engine Speed

WARNING: This page is about a different car, the 2008 GMC Yukon and 2008 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.

Cause	Correction
Review the system operation in order to familiarize yourself with the system functions. As required, disable the auto-stop function prior to repair. Refer to Hybrid Modes of Operation Description .
Low oil pressure	Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing . Repair or replace components, 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 push rod	Inspect the following components and replace, as required: The valve rocker arm The valve push rod The valve lifter The valve lifter guide The piston 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 valve rocker arm The valve push rod The valve lifter The oil filter bypass valve The valve is now internal to the oil filter. The oil pump and pump screen Restrictions within the engine block oil galleries
Broken valve spring	Replace the valve spring and spring shim.
Worn or dirty valve lifters	Replace the valve lifters, as required.
Active fuel management valve lifter with a broken spring	Replace the valve lifters, as required.
Improper operation of the camshaft position (CMP) actuator and/or control system	Repair, as required. Refer to Camshaft Position Actuator and Solenoid Valve Diagnosis and Testing .
Stretched or broken timing chain and/or damaged sprocket teeth	Replace the timing chain, tensioner, sprocket, and camshaft position actuator.
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
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 .