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 not to 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. | ||||
Improper operation of the active fuel management system | Inspect the system for proper operation. Refer to Diagnostic Starting Point - Engine Mechanical. |