What are the reasons for black smoke from diesel vehicles?

[DelSavannah]

Reasons for black smoke from diesel vehicles: 1. Poor diesel quality, where the performance indicators of the diesel used do not meet standard requirements, leading to poor fuel combustion and black smoke; 2. Blocked air intake, as the diesel engine's fuel tank is in long-term contact with air, causing the filter to block the air intake, preventing sufficient air supply during diesel combustion and resulting in incomplete combustion; 3. Insufficient compression force, as one of the conditions for diesel combustion is a certain pressure in the combustion environment. However, if components like valves and piston rings are worn, the compression pressure may be insufficient, failing to meet the required combustion pressure, thereby worsening combustion conditions and causing the diesel engine to emit black smoke.