The Causes And Solutions of Black Smoke Emitted by Diesel Engines

(1). Air filter clogged. Excessive dust and particulate matter in the air can cause the filter element to accumulate dust and dirt, increase intake resistance, affect combustion efficiency, and produce black smoke. The solution is to replace the air filter.

(2). Poor oil quality or carbon buildup. If the quality of the added diesel is poor, carbon deposits will be generated after combustion, hindering the fuel flow and causing poor fuel supply, resulting in a rich mixture and the generation of black smoke. The solution is to replace the fuel filter and use high-quality diesel that meets the standards.

(3). Insufficient compression force. After the valve, piston ring, and cylinder liner are worn, the compression pressure and temperature are insufficient, and the fuel combustion conditions become worse, which is prone to producing black smoke. The solution is to clean the blocked intake pipe and air filter, and if necessary, replace the damaged turbocharger.

(4). The fuel injector is not working properly. Poor spray quality, insufficient injection pressure or fuel injector leakage will make the fuel not fully mixed with the air in the cylinder, so that it cannot be completely burned, resulting in black smoke. The solution is to replace the fuel injector with a new one.

(5). The fuel injection pump is not working properly. Severe wear on the plunger or outlet valve of the fuel injection pump will lead to a decrease in pump oil pressure, delayed fuel injection, increased post combustion, and black smoke emission from the diesel engine. The solution is to replace the fuel injection pump.

(6). Excessive fuel supply. Excessive fuel supply results in a rich mixture and incomplete combustion. The solution is to reduce fuel supply by adding appropriate diesel to the diesel engine to meet the demand.

(7). Incorrect adjustment of valve clearance. Excessive valve clearance can reduce the maximum valve opening and shorten the opening time, leading to insufficient intake; If the valve clearance is too small, the valve is prone to air leakage, which affects the cylinder compression force. The solution is to adjust the valve clearance.

In addition, if diesel engines are used for a long time, it may cause component wear and affect oil and gas supply, and 4S testing is needed to confirm the root cause of the malfunction.