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Engine Mechanical – V6 Page 6A1–33
2.9 Upper Engine Noise, Regardless of N O T E A cold piston knock, which disappears in A light rattle/tapping noise may indicate a valve train/upper engine concern, while a low rumble/knocking may indicate a Cause Correction Low oil pressure. 1 Perform an oil pressure test, refer to 2.19 Engine Oil Pressure Diagnosis. 2 Repair or replace the engine oil pump as required, Worn or loose stationary hydraulic lash adjusters (SHLA) The SHLAs, rocker arm and roller bearings should be intact 1 Clean, inspect and replace the camshaft lash Stationary Hydraulic Lash Adjuster. 2 Replace the SHLAs and/or rocker arms as required, Arm. Incorrect lubrication to the stationary hydraulic lash Inspect the following components and repair or replace as valve rocker arms, refer to 3.20 Rocker Arm. • stationary hydraulic lash adjusters, refer to 3.21 Stationary Hydraulic Lash Adjuster. • oil filter by-pass valve, refer to 3.3 Oil Filter Adaptor. • oil pump and suction pipe, refer to 3.17 Oil Pump • cylinder head oil galleries, refer to 3.22 Cylinder Head • cylinder block oil galleries, refer to 4.7 Cylinder Broken Valve Spring. Replace the valve spring, refer to 3.22 Cylinder Head Assembly. Stretched or broken timing chain/s and/or damaged timing Replace the timing chains or sprockets as required, refer to Timing Chains, Tensioners, Shoes and Guides. Worn or faulty timing chain tensioner or guide. Replace the timing chains or sprockets as required, refer to Timing Chains, Tensioners, Shoes and Guides. Worn camshaft lobes. Replace the camshaft/s and SHLAs as required, refer to Camshaft or 3.21 Stationary Hydraulic Lash Adjuster. Worn valve guides and/or valve stems. Inspect and repair or replace valves and valve guides as Cylinder Head Assembly. Stuck valves. Carbon on the valve stem or valve seat may cause the Inspect and repair or replace valves and valve guides as Cylinder Head Assembly. |