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Why Is Blue Smoke Coming From The Exhaust?


Why Is Blue Smoke Coming From The Exhaust?

When something is off with our vehicle, it can make us feel nervous, uncertain, and worried. After all, many car troubles can be expensive, not to mention complicated. If you notice blue smoke coming out of your exhaust, what does it mean for your engine and wallet? 

Blue smoke coming out from your exhaust indicates that your engine is burning more oil than it should be, probably from an oil leak. Worn-out engine parts can also be a possible cause of blue smoke. Proper maintenance and upkeep are vital to keeping your engine running well. 

The rest of this article will discuss additional topics related to this subject, including common causes behind blue smoke coming out of the exhaust and how to fix it. 

Blue Smoke Coming Out of Exhaust Usually Indicates a Problem

If you notice blue smoke coming out of your exhaust, that could mean a problem. One possibility is that oil is dripping onto the headers in your engine. If oil is escaping from the gasket between the engine block, it could end up dripping onto the hot exhaust parts resulting in a smelly blue smoke emission from your exhaust. 

One way to tell if this is the cause of your blue smoke issues is to consider other symptoms. For example, is it just the blue smoke? Or are you noticing a foul odor as well? If you notice a terrible smell combined with the blue smoke, it could be an oil leak onto your exhaust parts. 

Read: Why White Smoke From Exhaust When Accelerating?

Oil Leaks

Another possible culprit behind the blue smoke is oil mixing with your vehicle’s fuel. Or, it could be from oil dripping onto hot engine parts. So pay attention to your car. Do you notice the blue smoke only when your vehicle is sitting idle or when it’s accelerating?  

If oil is dripping onto hot engine parts, it’s likely because a head gasket or valve cover gasket has gone bad, resulting in an oil leak. The oil drips onto hot parts of the engine bay, creating a cloud of blue smoke to come out of the exhaust when your car is accelerating, or blue smoke will come out of the hood when your car is just sitting idly. 

Engine Type

You may also need to consider what type of engine your vehicle has, diesel or regular when attempting to figure out what’s causing the blue smoke. 

Diesel engines, for example, with blue or black smoke coming out of the exhaust, could mean that the glow plugs are bad and need to be replaced. Usually, though, you can tell if this is the problem because your diesel vehicle will have a hard time getting started and will take longer to crank the engine. 

Read: 5 Reasons Why A Car Engine Knocks On Startup Then Goes Away

Other Causes

Another possible cause for blue smoke coming out of the exhaust is a worn-out engine with a clogged cylinder head. If this is the case, you just need to clean it. 

If your car has a turbo, and you notice blue smoke coming out of the exhaust, this could be a signal that your turbo is blown, likely because of a broken oil seal. 

Another possibility is that your vehicle is experiencing transmission fluid loss. This happens when a modulator, which controls transmission shifts in older cars, fails. Typically, this only happens in older vehicles, though. Buif this does happen, it can cause the engine to suck in transmission fluid, burn it, thus resulting in blue smoke coming out of the exhaust. 

If you have an older vehicle and suspect this issue, you’ll likely only see the blue smoke in the morning or when you first start your car. 

As you can see, there are many possible causes for blue smoke coming out of your exhaust. To determine the cause of the issue, you should observe your car. It also is critical to know what type of vehicle you have to determine the cause of the issue. 

When in doubt, carefully note your observations and consult with a mechanic. 

Sometimes, it’s hard to tell what type of smoke is coming out of the exhaust. However, the color can tell you a lot about what is troubling your vehicle. Check out this article from Firestone for more information. 

How To Fix Blue Smoke Coming From Exhaust

When something unusual happens with our vehicles, it’s easy to feel panicked. But so long as you remain vigilant and pay attention to your car’s needs, you can quickly get ahead of any issue that may pop up. 

It’s important to do regular oil changes to prevent oil leaks. Also, maintain your vehicle’s parts, especially the PCV valves, valve seals, and piston rings. These parts, in particular, weren’t meant to last forever; so, they’ll likely have to be replaced eventually, but proper care and maintenance will help them last.

If it happens right after an oil change, you may just have put too much oil in it. Drain it and start over again. You can also take your vehicle in for regular oil changes with your preferred mechanic. 

You can ensure your vehicle runs properly by paying attention to it. When you turn on your car, turn it off, or observe the details, essentially time your vehicle is in use. If you notice strange smells, unusual sounds, or anything out of the ordinary, inspect your vehicle and, if necessary, get it to a mechanic. 

It’s also essential to keep your engine clean. Blue smoke from the exhaust is almost always a sign of an oil leak. Usually, the blue smoke results from oil leaking into the engine or engine parts, as previously discussed. 

Also, remember to maintain your valve seals, glow plug, and PCV valves. Keep them clean and replace them when necessary. 

For more advice on fixing issues relating to blue smoke coming from your exhaust, check out this article from Car From Japan

Read: What Happens If You Put Too Much Oil In Your Car

Any Oil Leak or a Loose Gasket Can Lead to Blue Smoke

Blue smoke coming out of your exhaust likely points to an oil leak of some kind. Often, if blue smoke is spilling out of your exhaust, it results from oil mixing with gas in the combustion cycle. That oil is then being burned and pushed out the exhaust pipe with the rest of the partially burned fuel. 

If this isn’t the case, the blue smoke could also signal that a gasket isn’t sealed correctly. If this is the case, oil is leaking and causing smoke and potentially a foul odor. Be extra careful if you notice a horrid smell. Frequently, these oil smells can be damaging to your health. 

For more tips and tricks on this topic, check out this article from New Parts. 

Read: Is Driving With a Bad Oil Pressure Sensor a Good Idea?

Can You Still Drive With Blue Smoke From Your Exhaust?

One of the first questions that will likely come to mind if you notice blue smoke coming out of your exhaust is whether or not your car is drivable.

You can still drive with blue smoke coming out from your exhaust, although you shouldn’t because it could lead to further costly problems. Until you know what you’re dealing with, you should probably keep your car parked while you consult with a mechanic. 

The longer you put it off, the worse it could get, especially for your wallet. Waiting to address the issue will likely only make things worse. Early detection and efficient fixes could save you big money in the long run. 

If your car just needs a simple fix, check out this article from Car Treatments. 


When there’s an issue with our vehicles, it’s a significant stressor. We rely on our cars to get us from point A to point B, but if your vehicle is malfunctioning, getting it fixed pronto has to be your top priority. 

When blue smoke comes out of your exhaust, it’s likely because of an oil leak. However, where that leak is coming from depends on your car type and age.

Remember to pay attention to your car. If you notice something off, get it checked out by a professional. 

Read: Why Car Won’t Start in Neutral?

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