What Can Cause a Car Engine to Smoke?

What Can Cause a Car Engine to Smoke? This is a pertinent question that troubles the hearts of many. The smoke from a car engine is not loved by anyone. That’s why people are looking for ways to stop them. Success in handling this issue requires that you understand the root cause of the smoke being emitted from the car engine. You might ask yourself why we should fight smoke from car engines? The reasons are very simple. Vehicle exhaust fumes can severely irritate the eyes as well as the respiratory track. In short, it represents a great risk to good health by breathing it into the body. Carbon-fueled engine fumes contain carbon monoxide which is a poisonous gas. Prolonged exposure to diesel fumes, especially black or blue engine smoke, may lead to breathlessness and coughing.

Those who undergo a long-term repeated exposure to diesel fumes over a period of say twenty (20) years have a greater risk of having lung cancer. In order to work with diesel fumes while minimizing these negative effects, you’ll need to keep the work place well ventilated. You must also repair your car anytime its engine start over-sending out smoke. During static running, you should connect an exhaust gas scavenger system to the vehicle tailpipe. When working in a vehicle inspection pit, make sure that the exhaust gas scavenger system connected to the vehicle tailpipe is ventilated to a safe place in the open air. This will prevent fume from being drawn back into the workshop and affecting the people nearby. In order to prevent leaks, you should maintain coupling and flexible connections in good conditions.

What Can Cause a Car Engine to Smoke? – Everything you need to know

Let’s now answer the question on what can cause a car engine to smoke? A car engine can smoke for various reasons. We’ll classify the causes based on the color of the smoke as follows:

Three Causes of Car engine Smoke

Blue Smoke

Blue smoke from a car engine signifies burning oil. Such a situation can be caused by – worn rings – Valve stem seals – Not changing the oil for extended periods – A plugged PCV valve and – Too high an oil level. In such cases, when the valve cover is removed, there is much sludge which is built under it and looks like mud. With time, this mud turns hard as a brick.

The blue smoke results from all the oil going up into the valves during startup. When this oil goes up, it is unable to get back to the oil pan due to blockage by the sludge thereby resulting to smoke. All the oil going up remains in the valve covers because the sludge blocks the holes and makes returning impossible. In such cases, the oil drains from the valves into the combustible chamber thereby resulting to blue smoke. This situation will eventually cause an engine to lockup from lack of oil on the bearings and crank.

Black Smoke

If the engine sends out black smoke which smells like gas, it could be – the ignition or – spark plugs or – the wrong mixture in the carburetor or – the same thing in a fuel-injected vehicle with different components. In a fuel-injected vehicle, the mass air flow, map sensor, faulty fuel injector, fuel pressure regulator, cam sensor, ECM computer, or problem in the ignition circuit could result to black smoke.

White Smoke

If your car engine smoke is white and has no real smell, chances are high that the head gasket is blown. Such usually results from overheating the engine, and usually causes the oil to be saturated with water. In such cases, the oil is not effective at protecting the bearings and can easily ruin your engine. Hot gases entering the cooling system also contribute in overheating the engine. Also note that white smoke can as well result from a leak in the intake manifold runners. Such allows water to be mixed with the incoming air.