Sometimes diesel engines emit a white smoke while starting. The white smoke is due to unburnt fuel caused by improper heating.
Diesel engines need high compression and heat for fuel combustion. It can be especially difficult to start a diesel engine during cold weather. Diesels with an engine temperature below about 80 F. will produce some white smoke during the first few seconds after startup. The content of white smoke is finely atomized raw fuel and water vapor. Most diesel cars and light trucks have glow plugs that help to heat the engine.
If the glow plugs burn out or the glow plug control modules do not keep them on long enough for adequate heating, then the engine will get increasingly difficult to start and produce white smoke for several minutes until it warms up. The level of white smoke will reduce as all cylinders start firing normally.
White smoke during start up can be due to the following causes:
- Burnt glow plugs
- Incorrect Ignition timing
- Compression problems - If a cylinder has significantly lower compression pressure than others. Minimum compression pressure should be 275 psi at cranking speed.
- Blown Head Gasket
- Poorly sealed piston rings
- Leaky valves
- Cracked Head
- Cracked Block
- Injector is stuck or not working
- Clogged air filter
- Defective waste gate such as an actuator, vacuum line etc.
- Poor fuel quality
- Low coolant temperature
The major cause of white smoke is inadequate heat. The low temperature at which fuel burns within the engine causes white smoke emissions and can be corrected easily by installing a low cost heating system.
Our Automatic Engine heating system which along with standard pre-heating has optional simultaneous and post heating option and will eliminate white smoke emissions during startup.