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Home >> Buick >> 2007 >> Lucerne CX >> Repair and Diagnosis >> External Pages >> Different car >> Section 237 (Engine Mechanical - 3.9L) >> 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 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.
Upper Engine Noise, Regardless of Engine Speed

Cause Correction
IMPORTANT: The camshaft position actuator may make a slight tapping noise upon cold startup. This is due to the viscosity of the oil that has not yet warmed to proper operating temperatures and should be considered normal for the first 3.5 minutes for cold engine operation.
Engine oil level overfull, causing aeration Drain excess oil and adjust oil level to proper specification.
Low oil pressure
  1. Perform an oil pressure test. Refer Oil Pressure Diagnosis and Testing .
  2. Repair or replace as required.
Loose and/or worn valve rocker arm attachments
  1. Inspect the valve rocker arm stud, nut or bolt.
  2. Repair or replace as required.
Worn valve rocker arm Replace the valve rocker arm.
Bent or damaged push rod Inspect the following components and replace as required:
  • The valve rocker arm
  • The valve push rod
  • The valve lifter
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.
Worn and/or damaged valve rotators Replace the valve rotators as required.
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 timing chain tensioner (if applicable) Replace the timing chain tensioners as required.
Worn engine camshaft lobes
  1. Inspect the engine camshaft lobes.
  2. Replace the camshaft and valve lifters as required.
Damaged, broken or dirty, balance shaft sprocket teeth (if applicable) Inspect the following components and repair as required:
  • The balance shaft gear
  • The camshaft gear
  • The balance shaft rear bushing
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
Malfunctioning camshaft position actuator.
Improper viscosity oil, contaminated oil or a plugged or missing camshaft position actuator filter can cause the camshaft position actuator locking pin to malfunction.
  • Verify correct oil viscosity by changing the engine oil and oil filter and reevaluating the concern.
  • Inspect for a missing or plugged camshaft position actuator filter.
  • If filter is missing, replace the filter, replace the camshaft position actuator and change the engine oil and oil filter.
  • If filter is plugged, replace the filter and change the engine oil and oil filter.
  • If no problem is found with the camshaft position actuator filter, replace the camshaft position actuator and change the engine oil and oil filter.
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