Service Information

Cruze

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.

Worn hydraulic valve clearance adjusters

Replace the hydraulic valve clearance adjusters.

Improper lubrication to the hydraulic valve clearance adjusters

Inspect the following components and repair or replace as required:

•	The hydraulic valve clearance adjusters

•	The tappet

•	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 tappets

Replace the tappets.

Stretched or broken timing belt and/or damaged sprocket teeth

Replace the timing belt and sprockets.

Worn, damaged, or faulty timing chain tensioners

Replace tensioners

Worn engine camshaft lobes

•	Inspect the engine camshaft lobes.

•	Replace the camshaft and tappets 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