6 Causes of a Car Blowing White Smoke From the Exhaust

(Updated on August 25, 2021)

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.

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) Damaged Coolant Reservoir Tank

coolant leak

Another area that can leak coolant is the coolant reservoir tank. This is generally less common to leak, but it can happen if the reservoir tank were to get damaged or cracked.

Sometimes this will happen if it a mechanic is fixing another problem in the vehicle and accidentally damages the tank. In any case, you’ll need to replace the reservoir tank whenever it is damaged.

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.

51 thoughts on “6 Causes of a Car Blowing White Smoke From the Exhaust”

  1. I had my radiator cap blow off while driving the engine got so hot. I installed a new thermostat and flushed the radiator as well. My tailpipe produces white smoke now. Is this a bad sign for my motor?

    Reply
  2. I have a 2016 Toyota avensis diesel 1.6 the car was driving fine dpf full engine service needed came up on the dash stayed on for 2 days went off now the car is leaving out white smoke form the exhaust while accelerating and idling no smoking until car gets hot what would you think the problem is

    Reply
    • You may need to do dpf regeneration with a scan tool beacause soot content may have clogged your exhaust.if you don’t do it quickly, it may mess up your engine

      Reply
  3. My car shuts off while driving an steering wheel an breaks kinda lock up an white smoke comes out of my exhaust

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  4. My car has shot a cloud of white smoke twice serveral months apart. Both while accelerating. Both while around 3000 rpm’s. Thoughts?

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    • Did you find the cause? I’ve got a Chevy Cruze with the same symptoms. Shoot me an e-mail if you can. The 3000 rpm sounds common between us. My oil is good, but at times I’ll check it and it’s way up the dipstick. I can wipe it off and check it again and it’s Ok.

      Reply
  5. My car had a big white cloud coming from it’s exhaust a few weeks ago when I was driving up a large hill. A firefighter escorted me to my home city ~ 30 miles away (The smoke stopped after a couple miles past the hill). I have not noticed any more smoke since, although I also haven’t climbed a hill as big as that.

    I intend to use a combustion leak test kit, but I’m wondering – is it Is it possible to have the smoke happen only once, and not be indicitive of a greater issues (such as broken head gasket)?

    Reply
  6. I have a Mercedes Benz Viano 3.0 v6. When I put diesel in and the needle is above quarter its smokes. I will take it for a drive about 20 km and when I get back the smoking has stopped. It will be gone for about a month to 2 months and then start smoking again. when the fuel is between reserve and quarter it will stop smoking. the smoke has a bad smell to it as well. Can this be a result of faulty injectors .

    Reply
  7. I have 2015 Ford Focus…First sign of problem the Ac stopped..result of fan not working… Within same drive car got really hot and Warning light message to stop engine immediately showed on dash. I pulled into parts store.. added oil..coolant and drove. Within 5 miles engine stayed cool but now thick white smoke from exhaust. I did spill oil into spark plug reservois. I changed plugs wiped out oil..but car still smoking. Any suggestions????

    Reply
  8. HI
    BMW 320i touring 2006. I have random white puffs of smoke from exhaust. Driving along happens at approx 15min intervals. I have had a oil leak for ages 2 rocker gaskets, 2 vacuum pumps, o rings now rocker gasket and rocker cover about a week ago, seems to have cured leek but the puffs of smoke started a couple months ago. Thought the oil leek was the cause. Any ideas.Thank you

    Reply
  9. My 2015 Nissan Pathfinder started to have a cloud of white smoke come from the exhaust on startup, but went away in a few seconds. I parked the car for a few weeks, and checked all fluids, checked for any leaks, and ran Seafoam through the gas tank. I checked my plugs and all look great. Stopped smoking at startup so I drove the car to work. Now the smoke is continously coming out. It doesn’t smell like oil burning or sweet like antifreeze. The smoke is really thick. Any ideas?

    Reply
  10. after backing up my 2004 accord with a v-6 and shutting it off i went to retrieve stuff fro the trunk and noticed white smoke trailing from the tail pipes for 30 seconds or more. Haven’t notices white smoke at any other time though i don’t use it very often.

    Reply
  11. I bought a 2014 f150. It was from a used car lot.
    I noticed today ( cool) day and I did not use the ride 4 about 2 days alot of white smoke came out tailp, it subsided but continued to come out duration of drive. I found out that this ride came from an auction.

    Reply
    • See if the white smoke persists. If it’s a lot of white smoke, it could be a problem. A little white smoke on a cold day isn’t that uncommon, and not really a cause for concern if that’s the only symptom you’ve noticed.

      You can probably do a leak down test to check for head gasket failure if you’re concerned.

      Reply
  12. I have a uno 1986 model it is making thick white smoke even while driving non stop and it has a bad smell what can it be firstly

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      • My 95 Lexus had some fuel injection cleaner fluid put in a month or so ago , driving miles away from home it started to smoke out , did the fuel injectors clean out ?

    • One point hasn’t been mentioned. White smoke can be burning oil, can be a bad mix also. I had white smoke, thought it was injectors. I replaced the mass airflow sensor and it was gone almost instantly. Rich exhaust smell also disappeared. It’s a cheap enough part, you should at least pull it and clean it (w MAFS cleaner only) and see if that helps.

      Reply
  13. I have a 2002 Silverado and after driving for a while and shutting off, when I go to start it back up say 20 minutes later it blows white smoke for let’s say a minute then goes away. Thoughts??

    Reply
    • It could be a leaky intake manifold gasket or a leaky head gasket. I would do a bit of testing (or take it to a mechanic) so you know for sure before replacing anything.

      Reply
  14. My car was showing 70% oil life and so I put to bottles of oil in it. My car started blowing white smoke from exhaust. Went to get an oil change the next day and was told there was too much oil in there. They told me to drive the car around to get rid of the white smoke. Is that true? If so how long should I drive it around?

    Reply
  15. I am considering a Saab 9-5 and the seller says the white smoke, which clears up in less than a minute, is caused by the age of the turbocharger. Is this likely a cause, and what else might it be caused by?

    Reply
    • That’s plausible; I think those turbos are water cooled. I have a buddy who had a turbocharged beetle that would blow a little white smoke whenever he would get on the throttle. It wasn’t a big deal in his case (he knows how to rebuild the turbo).

      Basically white smoke can be caused any time coolant gets into the combustion chamber and blows out the exhaust. This could be from bad head gaskets, a leaking intake manifold gasket, turbo coolant lines, or even coolant leaks in the EGR system.

      Reply
  16. My 1999 chevy 2500 6.0 had no smoke until the say after i bought it smoked for hours and more when i hit the gas…next day no smoke when i go to return it
    …..any ideas? I thought maybe condensation at first but why one day and not thw next?

    Reply
    • I don’t know. You could do a leak down test, check the head gasket and intake manifold gasket to see if those are leaking. More troubleshooting is needed.

      Reply
  17. I have a 2017 Mustang GT. I have noticed a little bit more white smoke coming out (not super thick) and see i am leaking coolant on the ground. Is it possible I have an internal leak too like a head gasket?

    Reply
  18. My 2000 Ford excursion has over 200k miles. It’s been sitting for a while and we noticed it had no oil. Did an oil change and for the 1st 3 miles it was letting out white smoke, then stopped. It sputtering, but not getting hot. I believe it may be bad gas. What’s your thought?

    Reply
  19. Brother gave me his 2001 Ranger. I replaced the fuel pump and put about 60 miles on it. Today, ran about a 1/4 mile with no problem. When I got back in vehicle to return home. It was sluggish and was blowing more white smoke from tail pipe than a Britdestroyer running from the Bismark. No oil in coolant and no coolant in oil……

    Reply
    • 1/4 mile isn’t a long distance, especially if the vehicle has been sitting for any length of time. Bring it up to operating temp. Does the problem persist or get worse?

      Reply
  20. I have a 2001 ford escort I put 2 quartz of oil in it to get me by until I get the oil changed the next day and right after I went to crank it up it started smoking big clouds of smoke from the exhaust and it started puttin and cut off.. Now my battery won’t stay charged… What could that be?

    Reply
  21. I have a 1998 Buick Century and had some mild temperature gauge issues, my temp gauge would spike up to the 3/4 mark and then go back down to normal immediately. My coolant light came on but my coolant was never low. After a few days of that happening it actual overheated so I pulled over let it cool, filled it up with antifreeze and while I drive it home soon as it got to the normal temp it would die. Happened twice on my way home. I replaced the radiator, water pump and thermostat. It is still dying when it gets to the normal temp gauge. I haven’t drove it at all since I replaced all those things only let it run in the driveway. After all that and it sitting for about two weeks I go to start it and it’s blowing out white smoke and the temp gauge went up and died. I need help. What could be the issue?

    Reply
  22. Hey me and my dad did a oil change on the car the last owner didn’t do any oil changes on it so it had his first oil change and a while and when we finished and when we started the car it was blowing white smoke and when we hit the gas more white smoke comes out

    Reply
    • If the previous owner didn’t do any oil changes, any number of things could be wrong. How many miles does the vehicle have on it, and how long did the previous owner have the vehicle?

      Reply
  23. I have a 2014 BMW. Just recently about 3 weeks after my mechanic did an oil change My car started to throw white light smoke out one exhaust pipe. Called my mechanic explained was going on and he said oh that’s bad. It is probably burning oil which could be a oil gasket or a cracked blocked I can’t remember what he said I panicked when he said I probably about 6 thousand. After that I don’t remember what else he said. Now it throws out white light smoke but it disappears right away and does not smell. What is your opinon the matter.

    Reply
    • He can’t know what the root cause is or how much it’ll cost without doing some diagnostics on the vehicle (and nor could I). Could be anything from condensation (normal, not a problem) to bad piston rings (which require an engine rebuild, and will likely cost close to what he quoted you).

      If you’re concerned, it might be wise to pay to have the car inspected and the problem diagnosed. The cost is usually low (around $100-200) and that information is worth it; it could save you a lot of money in the long run.

      Reply

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