What Does Blue Smoke Coming Out of My Tailpipe Mean?

We here at Hummel’s Automotive Diagnostic & Repair would love to tell you that blue exhaust smoke is nothing to worry about but we can’t in good conscience do that. Blue smoke coming out of your vehicle’s tailpipe means your engine is burning oil and this is usually a very bad sign. In most cases, if your automobile is burning oil so much that you see blue smoke, it’s time for a new car. Let’s talk about the things your motor exhaust can tell you, including black and white exhaust or no exhaust at all.


If blue smoke means your vehicle is burning motor oil what does black smoke mean? Black smoke means your car, truck, SUV, or CUV is burning gasoline, and, yes, this is as dangerous as it sounds. A vehicle should never burn fuel in excess. If it does, there is something wrong with the engine and, as you might fear, the gasoline could catch on fire. This is why we recommend that you pull over as quickly as possible to a safe spot, shut off your automobile, and call for help if you see black exhaust.


Blue or black smoke is a bad sign and so is white smoke. If you see a little white exhaust coming out of your tailpipe on a winter morning, don’t worry. Think of it as your vehicle’s breath. If you see white smoke, however, at any time, you’ve got radiator fluid (coolant) leaking and burning. The most common cause of white vehicle exhaust is a cracked or blown head gasket and if you know anything about cars, you know how devastating this is. White exhaust and overheating also go hand-in-hand.


As mentioned above, if you can’t see your automobile’s exhaust, this is a good thing from an automotive repair standpoint. It is a bad thing from a safety standpoint, however. Vehicle exhaust contains carbon monoxide which, as you know, is a poisonous and deadly gas. You cannot see or smell carbon monoxide, so you should never run your vehicle in an enclosed space such as your garage. Clear exhaust smoke might not mean car trouble but it can mean illness and possibly death, so always be careful with vehicle exhaust.

If you’d like your exhaust system inspected or you have excess engine exhaust, call Hummel’s Automotive Diagnostic & Repair in St. George, UT, at 435-236-2185 to schedule a repair appointment. We’ll make sure everything is a-okay with your automobile.

Photo by Hirun from Getty Images Canva Pro

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