What Causes a Single-Cylinder Diesel Engine to Emit Black Smoke Under Load?
2 Answers
The reasons why a single-cylinder diesel engine emits black smoke under load may include the following: 1. Clogged air filter: Check if there is a large amount of dust scattered in the air filter and inspect whether there is a significant accumulation of dust inside the air filter housing. If there is excessive dust, the air filter should be cleaned or replaced. 2. High intake resistance in the intake pipe, leaks in the intake pipe, or blockage due to deformation from compression. 3. Turbocharger malfunction, insufficient speed, leading to black smoke emission: Since most construction machinery currently uses turbocharged engines, when the turbocharger fails, the symptoms and causes are similar to those of an intake system blockage.
I often encounter situations where a single-cylinder diesel engine emits black smoke under heavy load, which is mostly due to poor coordination between fuel and air. The most likely causes are insufficient air or excessive fuel supply. For example, if the air filter is clogged, the air intake decreases. Under heavy load, the diesel engine requires more fuel, but with insufficient oxygen, the fuel doesn't burn completely, naturally resulting in black smoke. Issues with the fuel system are also common culprits, such as dirty fuel injectors or improper injection timing, which can lead to excessive fuel injection and incomplete combustion, causing smoke. Additionally, if the engine is worn out, such as poor piston ring sealing or reduced compression ratio, it can exacerbate the problem. It's advisable to clean the filter and check the fuel system promptly; otherwise, prolonged operation under these conditions may damage the engine and affect its lifespan. If thick black smoke is observed, it's best to stop and rest the engine to avoid overloading, which can prevent engine overheating or smoke-related accidents.
