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 belt

Replace the timing belt and sprockets as required. Refer to Timing Belt Replacement.

Worn camshaft lobes

Replace the camshaft. Refer to Camshaft Replacement.

Improper valve lash adjustment

Refer to Valve Clearance Adjustment.