BAR AS 2398262 - Caterpillar

Probable Causes
Faulty accessory
Damage to valve train components
Failure of connecting rod bearing
Crankshaft bearingsRecommended Actions
Faulty Accessory
Isolate the source of the noise. Remove the suspect engine accessories. Inspect the suspect engine accessories. Repair the engine accessories and/or replace the engine accessories.Damage to Valve Train Components
Remove the valve cover from the suspect cylinder(s). Check the following items for damage: camshaft, valve rotocoil, valve springs, lifters, pushrods, bridges and injectors. Check for valves that do not move freely. Remove the cylinder head and inspect the valves. Replace any damaged parts. If damage has occurred, clean the following components: cylinder liner, piston and exhaust system. Replace any damaged parts.Failure of Connecting Rod Bearing
Inspect the connecting rod bearings and the bearing surfaces (journals) on the crankshaft. Check the piston pin for excessive wear. Replace any damaged parts.Crankshaft Bearings
Check the crankshaft and/or crankshaft bearings. Check the components for excessive wear.