What Causes Smoke from the Engine Hood?

[DeSamuel]

Smoke from the engine hood can occur under the following circumstances: 1. Small fuel injection advance angle: This leads to incomplete combustion; slight leakage in the cylinder liner or water in the fuel can also cause it. White smoke during cold starts, especially in low temperatures, is normal and should disappear as the engine warms up. 2. Air-fuel ratio imbalance: Decreased cylinder pressure; early fuel injection (excessive fuel injection advance angle) can cause black smoke; failure of the smoke limiter on the fuel injection pump can also result in black smoke during rapid acceleration; malfunctioning exhaust brake system. 3. Burning engine oil: Blue smoke from the car engine is often due to "burning engine oil." In such cases, check for wear in the engine cylinder liner, "stuck rings," ring alignment, aging or deformation of valve seals, excessive valve guide clearance, etc. This condition is usually accompanied by blow-by in the crankcase.