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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1043 (Engine Mechanical - 4.8L, 5.3L & 6.0L (Introduction)) >> Diagnostic Information and Procedures >> Upper Engine Noise, Regardless of Engine Speed

Upper Engine Noise, Regardless of Engine Speed

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Upper Engine Noise, Regardless of Engine Speed

Cause Correction
Low oil pressure
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 oil pump and pump screen
  • The engine block oil galleries
Broken valve spring Replace the valve spring and spring shim.
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 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