Tag Archives: soot

Damaging Effect of Soot on Diesel Engines!

There has been a continuing problem with diesel engine trucks emitting soot from their exhaust pipes and causing environmental pollution. In recent years, there has been significant effort and advancement by truck manufacturers and oil companies who are doing research to produce oil that will meet the ever-increasing standards to help reduce, or even eliminate, airborne contaminants in the environment.

What is Soot?

Generally speaking, soot is comprised of the impure particles of carbon that result from the incomplete combustion of a hydrocarbon. Formation of this contaminant depends largely on the composition of the fuel; therefore, manufacturers recommend the use of improved oil to help prolong the life span of the engine and to decrease oil change intervals.

It is very important to monitor and analyze oil contaminants to prevent premature oil degradation and failure of a truck’s diesel motor. Although soot contamination is not considered a symptomatic contaminant, it can be a root cause of new motor failure occurrences. In other words, it is very capable of causing premature engine failures – or worse.

Presence in Engine

The presence of this contaminant in an engine is normal. It is expected, however, that the manufacturer’s recommendations about mileage and service hours of the oil would be consulted. This would help in understanding that soot comes from the exhaust and when highly concentrated, it would be completely abnormal. This type of contamination may cause the following issues with a truck’s engine:

  • The generation rate directly affects combustion efficiency. A high soot load can be caused from excessive ring clearance, restricted air filters and poor ignition timing. An oil change may not necessarily be the solution for this combustion problem.


  • Deposits on the surfaces of motors that interfere with the efficiency of combustion as well as the economy of oil consumption.


  • Rapid wear of rings and cylinder walls, which can be caused by buildup in the grooves behind piston rings. During cold start conditions, carbon jacking can severely damage the rings.


  • If soot and sludge separates and is deposited on areas such as the valve covers, oil pans, and rocker boxes, this may risk the reliability of the motor.


  • High viscosity and other corresponding problems during a cold start as well as t he risk of oil starvation can be due to a high concentration level.


  • Newly-manufactured diesel engines are designed for lower emissions. This means that the injection pressure is higher which increases the sensitivity of abrasive wear caused by soot. Also, the amount of disturbing production is amplified with some of the new exhaust gas recirculation (EGR) systems.


  • This contamination can cause engine failure to develop over varying amounts of time. Usually, fuel/oil with moderate levels of contamination can cause sudden-death motor failure with its combination effect. While massive concentrations can cause sudden-death failures – and more problems – in this type of case, it can actually shorten the life span of the engine by almost 60%. This means that your motor’s lifespan could be decreased from 750,000 miles to 300,000 miles of lifespan with controlled soot contamination.

    The positive and negative side effects of a better filtering system in an engine have been an ongoing discussion among many manufacturers and oil companies. Oil filtering systems can help remove impurities from the lubricants even while allowing soot to mix with the oil which does not help in protecting the engine. Therefore, it is very important to monitor and analyze soot emission from a truck’s engine in order to maintain a longer lifespan for that vehicle. Don’t let soot damage your diesel engine!