Smoky Engine? Learn How To Identify The Cause

When you start your car’s engine, you expect that action to be somewhat uneventful. But what you don’t expect to happen is one or more big puffs of smoke coming from the exhaust!

Smoky engines can often get attributed to many different causes. Some are harmless, whereas others tell owners to prepare for impending engine failure! Have you noticed that your car’s engine has started smoking recently? If so, you might be getting worried at this point.


In today’s blog post, I will discuss the different causes of smoky engines, so that you can be better prepared for what might lie ahead.

Your car’s exhaust emits white smoke

Does this happen first thing in the morning, when the temperature outside is cold? If so, there is usually nothing to worry about. You see, condensation can build up inside of your car’s exhaust system.

When the exhaust system heats up, so too will the water inside of it. The result is steam, just like you would see from a kettle boiling, for example.

But if you get lots of white smoke when you drive, and the engine temperature is warm, this could denote a failed cylinder head gasket. These gaskets sit between your engine’s cylinder heads and the main block. If you drive a V6 or V8, for instance, you will most likely have two cylinder heads and gaskets to contend with.

The steam that gets produced is because of the coolant entering the combustion chamber. In other words, coolant is escaping into the cylinder itself. You might also notice a significant power loss at this point.

You can expect to pay anything between $500 to $1,000 to have a leaking cylinder head gasket replaced.

Your car’s exhaust emits blue smoke

If you see some blue smoke coming out of your exhaust tailpipe, that usually means oil has entered the combustion chamber. Just to clarify things, the only two things that should ever be inside of each cylinder is fuel (i.e. gas or diesel) and air.

  • One or more of your engine’s piston rings aren’t sealing;
  • One or more of your engine’s valve seals are leaking;
  • You have a cracked cylinder head or engine block.

The first and second problems are often caused by infrequent oil changes. Sometimes, they are also caused by incorrect or poor quality oil, and engine flush not getting used in some oil changes.

The third problem is usually down to engine abuse (i.e. driving the car too hard all the time). In some rare cases, manufacturing defects are to blame.

Your car’s exhaust emits black smoke

Black smoke isn’t as catastrophic or expensive to resolve as blue smoke. Black smoke is down to too much fuel entering the combustion chamber. Some unburnt fuel exists through your car’s exhaust system.

You will often see diesel cars emitting puffs of black smoke. If the problem exists on diesels and it’s quite bad, it could be down to a blocked diesel particulate filter.

I hope you have found this guide useful. Thanks for reading!

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