What Exhaust Smoke Tells You About Your Engine

Most people cringe when they see identifiable smoke coming from their exhaust. Yes, it can be a bad sign, but it can also just mean there is a minor issue.

Let’s humanize the car. The engine represents our internal workings. To evaluate them, we can just assess how we feel. We can then get an objective look by doing things like taking our temperature. Your car works much the same way. You may notice the engine misfiring or being unresponsive. One objective way to determine what is going on is to look at the smoke coming out the exhaust.

No Smoke

Obviously, this is the best possible result. It is also unrealistic. Even if you can’t see anything, smoke is coming out. It has just been treated and lost its color. This is also why you never run the car in a closed space such as a garage. Very dangerous.

Black Smoke

Black smoke is feared by every car own. This is odd. Black smoke is actually the best visible smoke you want to see. It is not an indication there is a big problem with your engine. Instead, it usually means the air to fuel ratio is off and the car is running to rich. A tune up and new air filter will usually solve the problem.

White Smoke

White is a good color right? Not when it comes to engines. White smoke is the sign of the devil…at least for your bank account. White smoke usually means the engine is burning coolant. Yes, the coolant in your radiator system. This is the sign of a damaged head gasket, warped engine head or a cracked head. None of these are good developments and you are looking at an expensive repair. The damaged head gasket will not put you back too badly, but the word “cracked” associated with anything in your engine will.

Blue Smoke

Blue smoke means it is time to go back to bed. Blue smoke is usually a sign of problems down in the important parts of the engine block. We are talking cylinder, piston or valve problems. The blue smoke comes from the excessive burning of oil and generally is a bad sign. The problem is you usually have to rebuild the entire engine. If you just try to do a bit, the new parts may create a better seal. This will add pressure to the engine compartment and blow out other worn parts that were not replaced.

Your car is going to burn oil and smoke as part of the natural combustion process. Take it easy on the engine, keep your oil topped off and change your oil and oil filter as recommended by the manufacturer. This should help you avoid smoking problems.

Dirk Gibson writes for DCJAutoParts.com - learn more about diagnosing car engine problems and other auto topics.