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What Causes Black Smoke From a Diesel Truck?

by Gisela Chavez

Diesel engines are a common alternative to gasoline burning engines because they are more fuel efficient and tend to last longer. Diesel engines have a higher temperature of combustion which allows them to convert 30 percent of fuel energy into mechanical energy. Taking care of your diesel engine ensures that it will continue to perform optimally for years to come. Learn how to troubleshoot possible causes of excessive black smoke coming from your diesel engine.

Dirty Air Filter

A common cause for a diesel truck to produce excessive amounts of black smoke is a dirty air filter. The air inlet is restricted which means there is not enough air entering the engine. If the engine is not receiving the amount of air needed to properly mix with the diesel fuel, it will burn more fuel and cause an increased amount of black smoke.

Old Fuel Injectors

Old fuel injectors can also cause your diesel truck to release excessive amounts of black smoke. Worn out fuel injectors pump too much fuel into the engine and do not allow a proper mixture of air and fuel. This improper air-fuel mixture is often referred to as a “rich” mixture. Rich mixtures cause the engine to produce greater amounts of black smoke.

Collapsed Intake Hose

An intake hose allows the engine to take in outside air and mix it with fuel to power the truck. For maximum efficiency, a diesel engine needs to have a proper mixture of air and fuel. A collapsed intake hose does not allow the engine to receive a proper amount of air and will cause it to burn more fuel. Burning excessive amounts of fuel causes a diesel truck to release more black smoke.

Poor Fuel Quality

If your truck is filled with poor quality diesel, it tends to release more black smoke. Poor quality diesel requires the engine to burn more fuel than normal to power the truck. Burning large quantities of fuel causes the engine to release black smoke.

About the Author

Based in Colorado, Gisela Chavez has been writing and editing since 2004. Her editorial experience ranges from editing technical documents to editing for “The Bloomsbury Review.” She earned a professional writing certificate from the University of Colorado, where she received a Bachelor of Arts in English and Spanish.

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