Worn or loose rocker arms

The rocker arm bearing end caps and/or needle bearings should intact within the rocker arm assembly.

Replace the valve rocker arms as required.

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 clearance adjusters.

Sticking lifters

Replace as required.