Incorrect fuel pump and/or injector calibration is the most common cause of excessive quantities of fuel soot. This category represents the total measurement of all solid and solid-like materials found in oil samples.
In diesel engines the primary portion of this measure is fuel soot, followed by metal particles and oxidation products. Incorrect fuel pump and injector calibration is the most common cause of excessive quantities of fuel soot in diesel engines. Accumulated soot can clog galleries, block oil filters and thicken oil until it becomes sluggish, therefore accelerating engine wear.
In non-diesel engines the main pollutants are wear debris and oxidation products.
| Causes | Effects |
| Incorrect fuel pump and injector calibration | Increased Wear |
| Poor quality fuel | Decreased engine performance |
| Incomplete combustion | Increased viscosity |
| Restricted air filter | Corrosion of metal parts |
| Defective injectors | Increased acidity in lubricant |
| Improper equipment operation | Restricted lubricant flow |
| Low compression | Blocked oil filters |
| Worn engine parts | |
| Low turbocharger boost |
| Recommendations |
| Ensure injectors are calibrated correctly |
| Check fuel pump calibration |
| Analyse driver/operating techniques |
| Check turbocharger |
