Causes and solutions of mechanical noise (knocking sound) and excessive fuel consumption in Caterpillar excavator engines.

1. Mechanical noise (knocking) in the engine The possible causes and solutions are as follows.

(1) The connecting rod bearing is damaged. Check the bearing surfaces of the connecting rod bearings

and crankshaft. Install new parts if necessary.

(2) The crankshaft is damaged. Replace crankshaft.

(3) Accessory failure. Repair components or install new parts.

2. Fuel consumption is too fast The possible causes and solutions are as follows.

(1) Fuel system leaks. The parts at the leaking place need to be replaced.

(2) Fuel and combustion noise (knocking). Slight increases in fuel consumption may be due to fuel

injector failure, engine roughness, or other factors that result in power loss. Refer to the “Engine

Misfires or Rough Engine” section and the “Engine Lack of Power” section.

(3) Fuel injection timing error. Adjust fuel injection timing.

(4) The fuel setting is too high. Adjust fuel settings.