Fuel soot is composed of carbon and is always found in diesel engine oil.  Laboratory testing is used to determine the quantity of fuel soot in used oil samples.  Stringent exhaust emission regulations have placed greater emphasis on fuel soot levels.  One of the most significant impacts of reduced emissions is a higher level of fuel soot in the oil.  The fuel soot level is a good indicator of engine combustion efficiency and should be monitored on a regular basis for possible maintenance action.

Soot CAUSE

• Improper air/fuel ratio
• Improper fuel injector adjustment
• Poor quality fuel
• Incomplete combustion
• Clogged air induction
• Defective injectors
• Improper equipment operation
• Low compression
• Worn engine parts/rings

Soot EFFECT

• Poor engine performance
• Poor fuel economy
• Increased operating cost
• Harmful deposits or sludge
• Increased wear
• Shortened oil life; Poor lubrication
• Lacquer formation
• Carbon deposits
• Clogged filters

Soot SOLUTION

• Ensure injectors are working properly
• Check air induction /filters
• Change oil
• Evaluate oil drain intervals
• Check compression
• Avoid excessive idling
• Analyze driving/operating conditions
• Check fuel quality
• Evaluate equipment use vs. design
• Evaluate operator experience/training

.