Smoke coming from the engine of your vehicle could point to a plethora of things, some of them not an immediate concern, others quite severe. Normally, if there is a problem with the vehicle, you would expect smoke to come from either the engine or the exhaust. Smoke being expelled from the exhaust is not as alarming as that which is flowing from the engine, as the engine is not designed to expel any waste gases from any component underneath the hood.
Waste gases are directed through multiple components to ultimately be expelled from the exhaust, after being separated from the oil. Any plumes of smoke that occur in the engine are typically more alarming than those that come from the tailpipe, but both can be identified and diagnosed by the color. Let’s take a closer look in the article below.
Identifying the Source of Smoke Based on Color
An important note about smoke coming from any part of your vehicle is that it is typically an indicator of a leak of some sort of fluid, whether that be coolant, oil, or fuel. The smoke is a sign that a given fluid has evaporated or burned either on a heated engine component or at some point in being sent to the exhaust.
In the case of leaking oil, it can also represent the failure of the oil-air separator to separate the oil from the waste gases. No matter the color, smoke coming from your engine needs to be brought to the attention of an experienced mechanic, as there can be many components that may have failed or malfunctioned.
White smoke can indicate a coolant leak in your vehicle. As coolant is a water-based solution, when it splashes or leaks onto the heated engine components, it quickly evaporates and creates a thick plume of white smoke.
It is important to note that there are two different kinds of white smoke. White vapor which is thin and almost clear is simply a result of condensation that has built-up on the engine components during cold weather or overnight. This is normal and not indicative of any problems with the vehicle’s functioning. The kind of smoke we are discussing in this article is not a natural occurrence due to weather conditions.
Blue or Gray Smoke
Smoke that is blue or gray in color is a sign that there is an oil leak. As the oil lands on engine components, it burns and gives the smoke either a blue or gray tint and also a strong odor. Oil can also be leaking into the combustion chamber and burn that way as well. This can damage your fuel efficiency and cause problems when accelerating.
When smoke that is escaping your engine is black, this is usually one of the more concerning colors. It doesn’t mean that your car is going to break down right away, but like the blue or gray smoke, it can be a sign of leaking fluids, a broken engine component, or a faulty gasket.
Black smoke can be indicative of a clogged or dirty air filter, which can come from many things. Failure of the oil separator to separate oil from waste gases can result in such clogging over time in addition to the excessive presence of debris in the engine. This can also mean that there is a malfunction with the air-to-fuel ratio. Other sources may be bad fuel injectors, faulty sensors, or more.