| Condition | Action |
|---|---|
| Worn accessory drive components (abnormalities such as severe cracking, bumps or missing areas in the accessory drive belt and/or misalignment of the system components.) | Inspect the accessory drive components. Repair or replace all damaged components. |
| Low oil pressure | Insufficient or poor oil supply to crankshaft and connecting rod bearings. Perform oil pressure test. Repair or replace all damaged components. |
| Leaking and/or sticking fuel injection nozzle (A stuck fuel injection nozzle can cause a noise similar to a damaged piston, rod or rod bearing.) | Inspect the cylinder balance with scan tool to help locate the cylinder that is the source of the noise. If you cannot locate the cylinder that is the source of the noise, diagnose the engine for mechanical damage. If it has been determined that the fuel injection nozzle is causing the noise, replace the fuel injection nozzle. |
| Loose and/or damaged crankshaft pulley | Inspect crankshaft pulley and pulley bolt. Repair or replace all damaged components. |
| Loose torque converter bolts | Inspect torque converter bolts and flywheel. Repair or replace all damaged components. |
| Loose and/or damaged flywheel | Inspect flywheel and flyweel attaching bolts. Repair or replace all damaged components. |
| Excessive piston pin-to-bore clearance | Inspect the piston, piston pin, and the connecting rod. Repair or replace all damaged components. |
| Misaligned or bent connecting rod | Inspect connecting rod and connecting rod bearings. Repair or replace all damaged components. |
| Excessive connecting rod bearing clearance | Inspect the connecting rod bearings, connecting rods, crankshaft and crankshaft journals. Repair or replace all damaged components. |
| Excessive crankshaft bearing clearance | Inspect the crankshaft bearings and crankshaft journals. Repair or replace all damaged components. |
Lower Engine Noise, Regardless of Engine Speed