7 Causes of a Car Blowing White Smoke From the Exhaust

(Updated on March 28, 2022)

If you see white smoke coming out of your vehicle’s tailpipe, then you should understand the various root causes to avoid any potential engine damage. One of two conditions is responsible for white smoke blowing out of your exhaust.

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In most cases, especially in the winter, some white smoke from your exhaust is perfectly normal and not something to worry about. But other causes may be cause for alarm. Keep reading to help understand why this happens and when you need to worry about fixing the issue.

Top 7 Reasons White Smoke is Coming From Your Tailpipe

If you are in the unfortunate situation where white smoke continues to come out of your exhaust after you’ve let your car warm up for more than a couple of minutes, then you could have some internal problems taking place.

It’s important that you address the issue soon so that your engine and exhaust system do not get damaged in any way. Here are 7 of the most common causes of a car blowing white smoke from the exhaust pipe.

1) Condensation Burn Off

white smoke condensation

If you notice white smoke coming from your muffler, don’t automatically assume the worst. You may not have to worry because it could just be the accumulation of condensation causing that to happen.

In these situations, you will typically see this white smoke come out on cooler days. The smoke should only be coming out in small amounts after you start your engine. Then after about 30 seconds to a minute, the white smoke should clear up. If this is the case then you have nothing to worry about.

2) Cracked Cylinder Head

Whenever your cylinder head is cracked or damaged, coolant will begin to leak out of it. This doesn’t need to be a big crack either. All it takes is a little bit of coolant to leak out and get mixed in with the engine oil.

Once that happens, the oil will become contaminated. The first sign of having contaminated oil is white exhaust smoke coming out of the tailpipe. As this continues, the white smoke will begin to have a sweet odor smell that won’t go away.

3) Leaking Intake Manifold Gasket

bad intake manifold gasket symptoms

Another area that can leak coolant is the intake manifold gasket. If your vehicle has water jackets that run through the intake manifold, a leaky intake manifold gasket could give you symptoms that are very similar to a head gasket leak, a cracked block, or a cracked cylinder head.

A bad intake manifold gasket is often cheaper and easier to fix than a bad head gasket. If you notice white smoke, make sure you do a bit of testing and diagnostics to figure out exactly which component is leaking. The cost of an inspection and diagnostics fee will pay for itself when you dodge an expensive repair bill for a part that didn’t need to be replaced.

4) Oil Leak

damaged piston

If oil were to ever leak out of your piston rings or valve seals, then it would flow into the internal combustion chamber along with the fuel. Once the fuel and oil get mixed together, it will cause to come out of the tailpipe. You’ll likely see a blue-ish color smoke from your exhaust but it may appear to be white smoke to some people.

You would obviously want to fix this leak quickly because if the engine components are not being lubricated properly by the oil, then they’ll start to get worn out and damaged rather quickly. This will cause a whole other flock of expensive problems that you won’t want to have.

5) Bad Fuel Injector

fuel injectors

The fuel injector is responsible for injecting fuel into the internal combustion chamber at the exact right time. If you were to have a bad fuel injector, then it would cause white smoke to form because the proper amount of fuel did not enter the chamber at the right time.

6) Engine Control Unit Error

bad ecu

If you have a faulty engine control unit or one that simply is glitchy, it may throw off the timing of the fuel injector. This doesn’t mean the fuel injector is bad or anything. It just means you need to fix or reprogram the engine control unit so that it can correct the timing of the fuel pump injector.

Often, you can simply unplug your car battery for a few minutes to reset the computer and the issue fixes itself. But if not, you would need to go to your dealership to get this done because it requires expert mechanics who are familiar with your vehicle’s engine to reprogram the engine control unit.

7) Cracked Engine Block

cracked engine block

The worst case scenario is that your entire engine block has a crack in it. These are the kinds of problems that will be the most costly to fix. You probably aren’t going to know which of these problems is causing the white smoke to get produced until you have a mechanic look over your vehicle and perform a diagnosis on it.

Conclusion

So basically, the only time you don’t have to worry about the white smoke is when it clears up within a minute or so of starting your engine. If the white smoke stays on longer than that, then you need to determine which of the other six causes above are the problem and hire a professional to fix it.

66 thoughts on “7 Causes of a Car Blowing White Smoke From the Exhaust”

  1. I have a 2017 Nissan Rogue Sport and white smoke comes out of the tailpipe on startup and the smoke stops after a minute or two . What can cause that ? Mind you , it didn’t do that until I took it in for an oil change by a mechanic that I told their boss I didn’t want working on my car . The car does not over heat and I still get a 5 star performance rate . My car have never smoked before I took it to the mechanic .

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  2. We have a 2007 EC90 V6..After finding car 2.5 quarts low put in 2.5 in ..someone else had been using the car . I was driving it no issues when oil low light came on causing me to put this in immediately. It was driven a little about our small town and another person drove it about 25 miles round trip when I noticed when cranking car white smoke came out tailpipe and when I drove for just a few hundred feet then it cleared up then if I stopped at stop sign or red light and when starting to accelerate white smoke came out for about 3 to 5 seconds. It was not cold and no smell of the sweet antifreeze smell. No coolant in oil no history of overheating. I checked oil still a little low so put in Slick Fifty and Head Gasket Sealer . It had 35 miles to empty on tank I got 25.00 in gas fr Shell added fuel injector cleaner. Notice car was running better than ever super smooth more power..really noticeable more get up and go. Sometimes I drove it to town and back stopping at red lights and back and no white smoke seen at all. Usually small amount at cranking and depending how long you sit idling the more white smoke comes out before there is none after several seconds of acceleration..warm weather. I put another 25.00 in Shell gas and more injector clearer in gas . What do you think this is ? My next step is mass air flow sensor. Any ideas besides that. The other people using car had been getting gas at Ingles.
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