Cause | Correction | ||||
---|---|---|---|---|---|
Worn or loose rocker arms The rocker arm bearing end caps and/or needle bearings should be intact within the rocker arm assembly. | Replace the valve rocker arms, as required. | ||||
Worn or bent pushrods |
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Stuck valves Carbon buildup on the valve stem can cause the valve to not close properly. | Repair or replace, as required. | ||||
Excessively worn or mis-aligned timing chain | Replace the timing chain and sprockets, as required. | ||||
Worn camshaft lobes | Replace the camshaft and valve lifters. | ||||
Sticking lifters | Replace, as required. | ||||
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 . | ||||
Improper operation of the active fuel management oil pressure relief valve | Repair, as required. Refer to Cylinder Deactivation (Active Fuel Management) Oil Pressure Relief Valve Diagnosis and Testing . | ||||
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 . |