What Are the Reasons for Difficulty Starting and White Smoke from Diesel Vehicles?
2 Answers
Reasons for difficulty starting and white smoke from diesel vehicles: 1. Low engine temperature: If white smoke appears during startup in winter, it is usually due to the engine temperature being too low and not yet reaching optimal conditions; 2. Water in the fuel supply system: If you place your hand behind the exhaust pipe and water droplets form when the white smoke passes over your hand, it indicates the presence of water in the fuel supply system; 3. Low air pressure in the engine cylinders: If the engine emits white smoke at low temperatures and black smoke when the temperature rises, it suggests that the air pressure in the engine cylinders is too low; 4. Low fuel injection pressure: If the engine emits grayish-white smoke and the vehicle lacks acceleration power after starting, it indicates that the pressure in the fuel injection system is too low.
Diesel cars are hard to start and emit white smoke. I've experienced this multiple times and concluded that the main issue might be a problem with the fuel system. For example, clogged fuel injectors or insufficient fuel pump pressure can prevent proper fuel atomization, leading to difficulty starting. Excess diesel then turns into white smoke during exhaust. Another common issue is low temperatures, especially in winter, when diesel thickens and burns incompletely, producing white smoke. Additionally, insufficient engine cylinder pressure—possibly due to worn piston rings or a leaking head gasket—can make ignition difficult. The air system is also worth checking, such as for intake blockages or turbocharger failures. I recommend starting with simple checks like fuel quality and the air filter. If that doesn’t help, seek professional repair promptly to avoid engine damage.
