What Causes Smoke from the Engine Compartment?
1 Answers
Engine smoke can be categorized into three types: white smoke, black smoke, and blue smoke. Below is an explanation of each scenario: 1. Generally, if a car engine continues to emit white smoke when warmed up, there are two possible causes: a small fuel injection advance angle leading to incomplete combustion, or slight water leakage in the cylinder liner and water presence in the fuel. However, white smoke during cold starts, especially at low temperatures, which disappears as the engine warms up, is a normal phenomenon. 2. Black smoke from a car engine may occur under the following conditions: an imbalanced air-fuel ratio; decreased cylinder pressure; excessively early fuel injection (an overly large fuel injection advance angle) can cause black smoke; failure of the smoke limiter on the fuel injection pump may also result in black smoke during rapid acceleration; or malfunctioning of the exhaust brake system. 3. Blue smoke from a car engine is often due to "burning oil." In such cases, it is necessary to check for wear in the engine cylinder liner, "stuck piston rings," ring alignment, aging or deformation of the valve seals, excessive clearance in the valve guides, etc. This condition is usually accompanied by crankcase blow-by. Severe oil discharge from the turbocharger can also cause some oil to enter the cylinders through the intake tract, resulting in "blue smoke emission."
