Worn or loose followers, valve rocker arms

The follower, valve rocker arm, roller bearing should be intact and in the proper position.

Replace the followers, valve rocker arms, as required.

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 chains or components

Replace the primary timing chain, secondary timing chains, intermediate sprocket, camshaft position actuators and/or related timing components as required.

Worn camshaft lobes

Replace the camshaft or camshafts and stationary hydraulic lash adjusters (SHLAs), valve lifters.

Sticking SHLAs, lifters

Replace the SHLAs as required.