5 Causes of Car Blowing White Smoke from Exhaust

Last Updated on July 5, 2021

If you start up a vehicle with a gas engine and you notice white smoke blowing out of the exhaust pipe, there are a few reasons why this could be happening.

Looking for a good online repair manual?
Click Here
for the 5 best options.

One reason for white smoke is very common and completely harmless. But there are other times when white smoke is coming out of your car’s exhaust that you do need to pay attention to as it can be a sign of a major problem.

5 Causes of White Smoke Blowing From Car Exhaust

#1 – Condensation

white smoke blowing from exhaust

This is a common occurrence, especially in colder climates. When it’s cold outside and you notice white smoke at startup, then you probably have nothing to worry about.

When the warm or hot exhaust gases meet cold outside air, condensation and steam is a result. After a short amount of driving, the white smoke should lessen.

It’s common for drivers who have lived in a warm climate like California and then move to colder region to worry about this but it’s harmless and perfectly normal.

#2 – Coolant Leak

If you continue to see white smoke coming out of the pipe after the engine has had a chance to warm up or while accelerating, then your coolant might be leaking internally.

The most noticeable symptom of internal coolant leakage is when the white smoke is billowing out of the exhaust pipe and leaves a sweet odor in the air. If you the white smoke consistently comes out and the sweet odor smell is present, then it is definitely a problem with your coolant leaking.

The reason why coolant usually leaks is because there could be a crack in the cylinder head or even engine block. Even if the crack is small, the internal coolant can easily leak out and contaminate the oil of your engine. This is how the exhaust smoke ends up turning white.

The combination of the coolant and engine oil will create a milky appearance in the smoke. All it takes is for just a little bit of coolant to get into the combustion chamber for white smoke to be produced.

Once you have a low coolant level and a cooling system that isn’t being maintained properly, your engine will begin to overheat. This will cause your head gasket to fail because they won’t be able to seal properly when they’re overheated.

As a result, your engine will get worn out much faster and its internal components will get damaged.

#3 – Piston Ring or Valve Seal Leak

symptoms of bad piston rings and valve seals

Leaking valve seals or piston rings are another possibility when it comes to smoke. In this case, bad seals or piston rings cause oil to leak into combustion chamber which then mixes with fuel and burns. The result is a white or light bluish smoke that comes out from exhaust manifold.

If you want to fix this white smoke problem, the easy solution is to take your vehicle to the nearest auto body shop as soon as you notice it. But if you are trying to fix this yourself, never try to remove the coolant reservoir cap with the car still running because the engine will be too hot and it will cause you serious injury.

Once the car has had a chance to cool down, check the reservoir and see what the coolant level is at. If the coolant appears to be at the normal level, then you’ll need to have a cooling system pressure checked performed so you can pinpoint where the coolant leaks are coming from.

#4 – Bad Fuel Injector

fuel injector replacement cost

A faulty fuel injector, usually one that is stuck open or is leaking from the o-ring, will deliver too much fuel to the combustion chamber. This excess fuel cannot properly burn in the engine and instead comes out as white or gray smoke out of your tailpipe.

Replacing the bad injector (or its o-ring) is the solution.

The hard part is figuring out which fuel injector is bad so depending on vehicle mileage, many mechanics will recommend replacing all the injectors since they’re not very expensive in most cases.

#5 – Incorrect Injector Pump Timing (Diesel Engines)

A diesel engine requires precision timing and fuel pressure of the injector pump. When the timing is not what it’s supposed to be, your engine will essentially be running rich which will cause fuel to not completely burn and instead exit out of the exhaust as white or gray smoke.

 

110 thoughts on “5 Causes of Car Blowing White Smoke from Exhaust”

  1. Hi, I repaired the car engine. It had a piston ring issue. But the white smoke still didn’t stop. It continues coming from the exhaust and smell like fuel. The repair was done by a repair station. I live in an environment which is like – 15. The repair station said it’s because of the cold. What shall I do? Wait till the summer and see whether it is still coming?

    Reply
  2. I have white smoke coming out of my exhaust and I was told I need a new high pressure gas pump. I am not sure what this is. Is it a fuel pump? Can you give me any information about this because I don’t see this as a common problem as to why white smoke is coming out of my exhaust.

    Reply
    • What year, make, and model of vehicle are you driving? I can’t know if it’s a common issue unless I know that information, because some vehicles are more prone to certain types of failures than others.

      Yes, I assume by “high pressure gas pump” they mean a high pressure fuel pump (HPFP). Direct injected engines typically have a low pressure fuel pump to bring fuel from the gas tank to the engine bay, then a high pressure fuel pump that sends fuel at very high pressures to the fuel injectors, which then inject fuel straight into the combustion chamber.

      I don’t think the white smoke would be caused by a bad fuel pump, but you’ll have to look into the problem a bit more to know for sure.

      Reply
  3. I only have white smoke coming out of my exhaust pipe after the car is sitting running / idling for about an hour and the smoke only comes out when I step on the gas and only does so for about a minute and then completely goes away. This is the only specific time and way the smoke comes out of the exhaust pipe. If I do not sit idling for an hour then nothing happens. any thoughts?

    Reply
    • Do you have a turbocharger? It’s possible the cooling lines in the turbo are leaking a bit. You could perform a leak down test to help you eliminate bad head gaskets as a possibility. Any other symptoms? Does the issue affect the car’s drivability?

      Reply
  4. My 1993 acura legend has white smoke blowing from the exhaust and green liquid in the engine. Big old cloud of white smoke when the car turned on. Is it a bad water pump or blown gasket?

    Reply
  5. My 2012 Nissan Qushqai is pouring smoke when ever I turn it on and accelerate I don’t know if this is because the dpf not cleaning properly or a coolant leak what do you think I should do?

    Reply
  6. I noticed a white smoke coming out of my golf 3 car, the moment I accelerate it brings out the white thick smoke. Please what is actually wrong with the car,?

    Reply
    • It will be hard for anyone to give you more information than what’s in the article without doing some diagnostic work to narrow it down. You could try doing a leak down test to confirm a blown head gasket. Sometimes a bad intake manifold gasket will exhibit similar symptoms, as will a cracked block or cracked cylinder head.

      Reply
  7. I have a 2000 chevy tahoe 5.7l i can drive it for about an hour or so. When I stop at a light after that time frame it begins to smoke. When I press the accelerator pedal and take off it goes away. I’m wondering if it could be my head gasket or a bent vavle

    Reply
  8. Hi.
    I have a -03 Passat 1.8t. Got a problem where I couldn’t Rev more then 3000 and before I was able to stop I noticed a big cloud of white smoke from the exhaust. When checking for faults I found a broken vacuum hose to my turbo and that the “fan” in the turbo was loose. Change the turbo now, got about 500m before the white smoke came back. Coolant is ok, oil ok. Smoke smells a little burnt. Got any idea?

    Reply
  9. My car smoke in the morning when start it up real bad I can’t see out my back window for about 5 minutes after that it’s OK it do this every morning real bad

    Reply
    • There are a number of things that could cause smoking, particularly on startup. You may have a head gasket or intake manifold gasket leak and are burning coolant.

      Reply
  10. Hi
    I have VW Golf 2002 Diesel, on startup it releases white smoke, after driving sometime it doesn’t release the white smoke anymore and seems fine. Then turning off the engine and starting again, it doesn’t release the white smoke, but when I keep the engine off for few hours and starting again it releases the white smoke again.

    Kindly advise.

    Reply
  11. I have an 04 Nissan Xterra…. I know there’s an oil leak somewhere (the truck was gifted to me -rather than junked after an accident causing some front end damage, but has run great til recently)…. This afternoon I started it and could hear the clicking that I was told means I need oil. Put some oil in, and now every time I accelerate, white smoke comes out the exhaust. So much that I kinda panicked, and parked, and took a Lyft home ….

    Reply
    • Is it leaking internally (into the engine), externally (onto the ground), or both?

      If it’s an internal leak, I would do a leak down test to figure out where that leak is coming from. Perhaps it’s burning oil (worn rings, excessive blow by) or perhaps some of the valves aren’t sealing correctly.

      If it’s an external leak, they make UV dyes you can put in the oil that will make it significantly easier to track down the oil leak. All you do is add the dye and shine a black light around the engine after letting the oil and dye circulate for a while. It may help to clean up the engine bay before you do this so you can see which leaks are new and what’s an old oil stain.

      Reply
  12. Hi I have a 2009 VW Tiguan tdi 4motion with only 58 thousand miles. It’s giving off white smoke from the exhaust too.

    The garage carried out a compression test and came back as ok.
    They said there’s fluid leaking at turbo to DPF clamp. So they suspect an internal leak somewhere.

    They said they need to remove cylinder head to investigate.

    What could it possibly be? Hose pipe O rings? Or something more serious? I drove it back from the garage.

    Reply
    • I don’t know. Sounds like your mechanic is on the right track, though.

      A leak down test would rule out head gasket failure. You could have white smoke from coolant leaking into the turbo or coolant leaking into the combustion chamber, either via the head gasket or intake manifold gasket (assuming your intake manifold gasket has water jackets).

      Reply
  13. Hi. Could you PLEASE email me!! I have a smoke problem with my vauxhall astra, it’s coming from the exhaust and I really need someone to advise me 🤞🏼🤞🏼🤞🏼🤞🏼

    Reply
  14. I have had non stop problems ever since I had an injector seal replaced, a new water hose and a new DPF filter fitted. The filter full continue driving warning light kept coming on a few days after having a new one fitted, weird right?! Then I started seeing white smoke coming out from my exhaust on starting the car and then every time I accelerated plus coolant level low warning light even though the tank was full. I took it to a garage they said the guy who fitted my DPF filter obviously didn’t know what he was doing as I had a split vacuum line which he would have noticed when fitting the new filter. The car was fine for about a week after that then the smoke started again, to the point where cars were holding right back away from me when pulling off as it was letting off so much. I took it back to the same garage who fitted the new vacuum line, they done smoke tests etc said it was fine but did come across a hole in my exhaust pipe so they repaired that. The car was again fine for about a week. Ever since I have had the coolant low warning light come on every time I get in the car and the smoke has started happening again! When I first start the car it let’s off a huge cloud and then when I accelerate going up gears it does it then too. I have no idea what to do or where to go from here! It seems the guy who fitted my new filter and water hose etc clearly didn’t know what he was doing because ever since he touched it I’ve had non stop problems. Nothing like this before!

    Reply
  15. I have a 2015 Chevy Camaro 6 cylinder with 65000 miles. I noticed yesterday after my car sat for an hour, I decided to go to a fast food drive thru and while waiting I noticed white thick smoke coming out my exhaust pipe, then when I pulled off the white smoke went away. Any idea what could cause this? This is the first time I’ve noticed this. Just wanna get an idea what it could be before I take it to the Chevy dealership and have them charge me 8,000 dollars lol

    Reply
    • It’s honestly hard to say without taking it in somewhere to have them look at it. The diagnostic fee shouldn’t be bad, probably around $150. Independent shops tend to be cheaper than dealerships.

      Reply
  16. 2010 mazda CX7.. the oil pressure light came on and then the check engine light.. I checked and my oil was a bit low.. I added some oil.. but when I read things on this car, most said it should be the VVT Solenoid.. which I am changing now.. I did open it up and noticed it looked a bit bad.. so I’m hoping that will fix it. But I am having white smoke coming out since the oil pressure light came on.. any ideas?

    Reply
    • I would check the oil pressure using an external gauge to see if you are actually experiencing low oil pressure, or perhaps a sensor or wiring has gone bad.

      Not sure on the white smoke. How much do you see? Is it only present on startup, or do you also see it when the car is at operating temperature?

      Reply
  17. I just changed the VVT solenoid and I’m hoping the oil is good now.. it seemed bad and oil all over it when I replaced it… the oil had gone down, so I just added oil to it now. Hopefully it holds. As I drove it about 1 mile it was smoking a lot out of the exhaust. Someone told me it could be burning the excess oil that already leaked out. I do see a good amount of condensation in the exhaust pipes and it leaking on the ground. I sealed everything well, let it run for about 30 min. Nothing seems to be leaking. But I do notice w kind of low pitch noise when I give it gas. Kind of loud. Hard to explain the noise. So not sure where to go from here..

    Reply
      • Was losing oil.. the oil pressure light was coming on.. and most threads I read for the vehicle with p0012 code said that the VVT solenoid was a possible issue.. also, we were hit with a big storm and I drove through high water not seeing it.. about a week later I started to see white smoke and a kind of deep whistle noise when I accelerated.. does any of this help?

        Reply
        • That is useful information. I’m not sure if it’ll be just a VVT solenoid or something else.

          I would take everything you said and run it by a local shop. A small diagnostic fee for the shop to take a look at it could potentially save you a lot of money when the alternative is throwing the “parts cannon” at the problem. The parts cannon gets expensive pretty fast, and a diagnostic fee is usually only around $100-200.

  18. 2003 Ford Explorer periodically emits thick grayish/white smoke with an odor. On start up water drip from tail pipe. Coolant level is full, oil is full. No leaking or staining on the motor or under the car on the ground. At a loss, any ideas?

    Reply
  19. hi, i have chevy camaro 2010 3.6L the engine was rebuilt and everything was new we took only the shell , so far when i drive the car i smell burned oil and then when i stop at the traffic lights havey some comes out of the exhaust , and some times driving for long time still smell the oil then stop in parking lots idling for 20 min then havey some again 3 to 4 time raving the car then drive the havey smoke gos away driving no smoke but still smelling the oil , what will be your thoughts please advise, i appreciate your email if you can, thank you .

    Reply
    • Sounds like you might have a slight oil leak somewhere, but that really could be anywhere. See if you’re leaking oil from the valve cover onto the exhaust manifold. If you can’t find anything, they make UV dyes you can put into the oil to help you trace the source of leaks. Good luck on your search.

      Reply
  20. I have 2017 infinity qx60 with 52000 miles. Once in a while on first startup noticed white smoke in exhaust pipe. Changed the pcv valves.no oil leak or coolant leaks. Mechanic suggested more frequent oil change. Will it help. Thanks
    Shan

    Reply
    • I don’t know. You could always try a used oil analysis if you’re worried about your oil change intervals. They test your oil to tell you what metals are in your oil, how your engine health is, and how long your oil change interval should be.

      Reply

Leave a Comment