Car Smoking from Exhaust Pipe?

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types of exhaust smoke Do you have smoke coming out of your exhaust? Evidently many TrustMyMechanic fans do, because this is one of the most frequent “Help!” messages I get…followed by:

What does it mean?
How alarmed should I be?
Is it safe to drive my car to work?
What in the world is THIS going to cost me???

After I talk them down from the ledge, I take them through a series of questions to help determine what is going on. A smoke-producing tailpipe is never what you want to see happening to your car, but it doesn’t always mean that there is something serious wrong with your engine.

First, watch the exhaust with the car running to determine the color of the smoke. There are three types of smoke your car may be producing: white, blue, and black, and you can get a lot of information just from the color.

White Smoke

White smoke is produced when antifreeze and/or water leaks inside the engine cylinder, where the gasoline is being compressed and burned. The smoke is actually steam caused when this coolant gets burned up with the fuel. Any amount of coolant present in the cylinder will produce this white smoke, which will get exhausted out the tailpipe.

If it’s white smoke you are seeing, examine the radiator and overflow container to find out if you have the right amount of antifreeze. Then check your engine oil dipstick and the underside of the oil cap for signs of antifreeze contaminating your oil. Your oil will look like a chocolate milkshake if it’s got antifreeze mixed in with the oil.

If you see any evidence of antifreeze in your engine oil, DO NOT start the engine. Your car probably has a blown head gasket allowing the fluid to leak in, and you can cause serious (expensive!) engine damage by running the engine. The head gasket usually fails because of excessive heat and pressure when the engine overheats. You will need to repair the head gasket and determine/repair the cause of the initial engine overheating before you can drive this car.

If you are dealing with white smoke, don’t miss this video with invaluable information on your problem and how you can save thousands on this kind of repair.

Blue Smoke

Blue smoke is created when oil leaks into the engine cylinder where the gasoline is being compressed and burned. As with the coolant causing white smoke, any amount of oil in the cylinder will cause blue smoke from the exhaust.

There are several gaskets, seals, and O-rings that can fail and allow oil to get inside the engine cylinder. This kind of oil leak is fairly common in higher mileage cars just from the wear these parts have experienced.

Unlike white smoke, you can continue to drive a car with blue smoke without causing immediate damage to the engine. A common remedy is to put in heavier weight engine oil and a special oil additive that can help reduce the oil’s ability to leak into the cylinder.

Excessive oil in the cylinder will foul the spark plug and cause the engine to miss or “misfire.” If this occurs, you will have to clean or possibly replace this spark plug.

Black Smoke

Black smoke is produced by excessive fuel in the engine cylinder. If the car is letting too much gasoline into the cylinder, the engine can’t use it all as fuel fast enough, and the excess gasoline causes this black smoke as it heats and burns. Your car is said to be “running rich” and of course results in pretty bad fuel mileage.

Even though it is the scariest to see, black smoke is actually the least cause of alarm. But, before driving the car again, check the oil dipstick and cap (like I mentioned before with white smoke) to make sure the gasoline hasn’t contaminated your oil. If there is gasoline in the oil, the oil won’t change color but will be much thinner and more “watery” than it should be, and you should be able to detect a raw fuel odor. DO NOT start the engine if there is any indication of fuel in the oil or you can cause internal damage and possibly catch your engine on fire (yes, I learned that the hard way).

There are several parts that may have failed to allow the excess fuel in the engine cylinder. You may have a faulty fuel injector, a damaged fuel pump, or a carburetor problem. It can also be a malfunction in the car’s computer or a computer sensor. You will need to have the car repaired to correct the cause of the smoke and odor, poor fuel mileage,and sluggish engine performance, but as long as the fuel hasn’t leaked into your oil, you can still drive the car until you can get this done.

I hope that this information has been helpful to you in determining the type and possible cause of the smoke coming out of your exhaust system. Make sure to pass on everything you have already determined about the problem and symptoms to your mechanic to aid in his quick diagnosis and repair of the car.

Blessings,

Austin Davis

31 Responses to Car Smoking from Exhaust Pipe?

  1. Hummmm, you got me. are you sure the smoke is white? Usually white is from burning coolant…is the radiator full? I wonder if the PCV system is stopped up, I don’t recall if you have a replaceable PCV valve or not….but might be worth while checking….ok, looks like it does http://www.jcwhitney.com/1999-2001-volkswagen-golf/replacement-oe-replacement-pcv-valve/p3068007d17621y1999-2001j1.jcwx

    I would start with replacing the valve and see what happens. The PCV system is how the engine breathes, and if stopped up it builds up too much pressure internally in the engine which can damage internal seals and orings.

  2. chris says:

    My 1999 vw golf has oil light on so topped it up with oil now white smoke coming from tail gate also a burning smell of oil but when I take the air filter off the smoke stops????

  3. I am not much of a diesel mechanic, sorry. I would get a cooling system pressure test to rule out a possible internal coolant leak though. You said there are no leaks, but just a small coolant seep can cause this smoke. If no leaks, could be an injector pump issue or an injector itself. You really need to see a real diesel mechanic to investigate further…sorry.

  4. Terri says:

    Can you advise please I have 7 seater galaxy diesel 99 and it keeps smoking from exhaust it’s white / grey colour have changed head gas: and head not warped not losing water not sure why it smoking. Thanking you in advance for any advise.

  5. Usually a valve stem seal is the culprit….but that is just a guess without pulling the cylinder head for inspection and doing a compression test on all cylinders. Depending on how many overall miles are on this engine, it might not be a good financial decision to spend more money on overhauling it???

  6. Tichaona says:

    I have a Toyota Harrier 1MZ engine, which produces a bluish smoke on start up everytime the car is idle for over an hour. I had the piston rings and valve stem seals changed (no sleeving was done) and the problem persisted. The other problem is oil level goes down and I have had to top up oil all the time. Please help.

  7. Sorry for my delay Ken, been swamped with questions lately. BLUE smoke is usually due to burning engine oil inside the cylinder (s) so I would probably start with pulling the spark plugs, and looking for a plug(s) that are black with engine oil, then on those cylinders do a compression test to see if the compression in those cylinders matches the others. Using thicker weight engine oil might help slow down the oil burning, as well as making sure the PCV system is working properly and allowing the engine to breathe.

  8. ken says:

    Hi,
    i reside in Kenya in Eastern Africa Region.
    my 1997 Mitsubishi galant (GDI)runs just fine.
    However recently there is blue smoke with a slight choking smell out of the tail pipe that comes and goes.
    recently i was travelling for a long distance and at some point the car could not accelerate(engine miss if i could call it so).
    after arrival and parking overnight i traveled the same distance back home with no hitches at all.
    kindly would you assist me in knowing what might be wrong.
    ed.
    your support is highly appreciat

  9. Thanks Dave!

    Did you have to add any coolant to the radiator? Do you have any engine oil leaks that might be running down on the hot engine producing smoke under the hood? How about the brakes? I have seen front brake calipers stick and cause the pads to stick to the brake rotors while you are driving and cause the pads to overheat…and produce smoke and a strong odor. Check to make sure one of the 4 wheels is not significantly hotter than the others after you have driven around for a while.

  10. Dave Snider says:

    Hi Mr. Davis,

    I’ve got a quick question.
    We’ve I got a 2002 F-150 4×4 with about 145,000 miles.
    It runs great and has been very loyal to us. Lately, after a ride around town running errands or going out to dinner, we come home and pull into the garage. I step out of the truck and the 2 car garage is filled with lots of white exhaust smoke. It appears fine when we’re driving around and every year it passes inspection with flying colors. Would you have an idea why I step out into a cloud of smoke when I exit the vehicle? I will check the radiator fluid after I send this question to you.

    Thanks for your time and knowledge.

    Dave

  11. Sure thing Robert, although before you do anything get a cooling system pressure test to rule out an EXTERNAL leak. I get tons of emails each day about headgaskets and more than half are NOT a head gasket problem. I have two videos here I want you to watch.

    http://www.trustmymechanic.com/4429/head-gasket-sealer-try-this/

    Let me know if you need more help

    Austin

  12. robert says:

    I have a headgasket leak, would like to know your great alternative to costly repair.

    I have a 2000 honda civic with over 230,000 miles. I lose about a quart or more of radiator fluid about once a week. I do notice white smoke every time I start up, but it (majority) of smoke disappears after 2 minutes of warmup. on warmup I have to slightly press the gas, otherwise I will have misfiring, I think this is cause I have radiator fluid in one or more of the cylinders, after warm up the car runs fine and idles regularly around 675-760rpm. hope to get this car to last another 12 months, so I can save enough for a downpayment on another car. would love to know your alternative repair method, thanks

  13. Hi Charles,

    Hummmm, sounds weird for sure. 160,000 on one of the vehicles does not concern me too much they are well built and have a great service record. The mifire code, yes it can be a problem with an injector, either dirty or just faulty internally. This does not concern me that much either since its not a constant issue.

    Now, the noise and possible smoke does concern me and I would advise you not start or drive it but have it towed to your mechanic for inspection as to not do any more damage.

    Hopefully this is something external like the water pump broke and the belts are off….check for that. Since you did not mention overheating hopefully this is not an internal coolant leak issue like a blown headgasket. Check the engine oil level, is it full and clean looking?

    If the fan belt is still connected, then we need to start thinking of internal items that would cause the noise….oil pump failure, cam or crankshaft failure etc.

    I would rather not place any fear in your head at this point, so start with the basic stuff, belts attached, all vacuum hoses and wire connections attached? Can you see any oil or coolant leaks etc. etc.

    Get back to me if you find anything out yourself, or when your mechanic has time to diagnose this and we can see if you have any options available to you.

    Austin

  14. Charles S. says:

    Hi. I have a 2006 Ford Explorer with 160,000 miles on it. Every once in a while it will miss when I start it. I can drive it a mile or 2 and turn it off and restart it and it runs like a charm. My check engine light comes on and I had it hooked up to a computer….it says “cylinder 1 misfire”. I changed the spark plug and the coil. Neither one fixed the problem. It doesn’t do it all the time…just on occasion. I figured it had something to do with the injector probably. Last night while driving, it was running fine and all of the sudden it started making a horrible sound like it had no oil…like metal to metal and it died. I pulled over and when you tru=y to start it..it will rev way up and then die. Also, white or blue ( it was dark) smoke will boil out of the tailpipe. The inside of the tail pipe looked like it had a watery substance in it. Any idea what may have happened?

  15. Thank you for your comment Christopher, you made my day.

  16. christopher says:

    Dear Austin Davis,

    Just wished to let you know that reading this site is really helpful for me. At least I now know the reason of the white smoke from my car. TQVM….from the bottom of my heart!

  17. Austin Davis says:

    Welcome, same to you.

  18. Gantulga says:

    Its engine cold.thank you for everything.Good luck to you.

  19. Austin Davis says:

    Are you sure this is BLUE smoke from burning oil (are you adding engine oil regularly) or could this be a more BLACKISH colored smoke due to running rich, too much fuel. If this vehicle has a carburetor, maybe you have a choke problem which would happen when engine is cold and the smoke is a darker black color due to unburned fuel?

    Even fuel injected vehicles have a cold start injector or cold start function to help start the engine in cold weather.

    I dont really think blue smoke issues would cause the engine to die, unless there is severe internal engine damage causing loss of compression.

  20. Gantulga says:

    there is 1 misunderstanding.My car not stop by itself.
    When blue smoke comes up.
    I stop the car.
    then restart everything normal for few minutes.
    today smoke comes up 1 time.
    Yesterday 3 times.

  21. Gantulga says:

    Thank you very much.I have no garage.Then I thought car is cold something like that.Is this possible

  22. Austin Davis says:

    If its BLUE smoke you see then you are consuming (burning) engine oil in the cylinders. If the smoke seems to happen more so when you come to a stop than when you are driving I would suspect a problem to be more so in the cylinder head (like valve stem seals) than due to wear in a piston ring.

    You might want to try using thicker weight engine oil (since it gets very cold there, you can’t use too thick of oil weight) like maybe a Castrol 20w-50 and an oil additive called Engine Restorer, to help slow down the consumption. It might never go away completely without doing internal repairs to the engine but might reduce it enough where it is livable.

    Here is a link to their product page for more information
    http://www.restoreusa.com/faq.html

    You might have to order it on ebay or amazon if you can’t find it locally.

  23. Gantulga says:

    Hi my name is Gantulga im from mongolia
    My car is Sang yong Actyon 2009
    The problem is blue smoke
    when i drive and stops its coming out
    Early in morning
    2-3 times coming out
    I havent get my winter oil yet
    what is the problem
    Thank you

  24. Austin Davis says:

    I would suspect you have worn out valve stem seals in the cylinder head. Stem seals tend to leak oil when the engine is off and sitting up. When you start the engine after it sits the cylinder and spark plugs have to burn off the oil that has seeped into the cylinder, thus the blue smoke….from burning oil. The correct fix is to remove the cylinder head and do a “valve job” but that is very expensive.

    You might try using a thicker weight engine oil, like Castrol 20W50 weight and see if that slows down the oil seep. Also have a mechanic check the PCV system, which is what the engine crankcase uses to breathe. If the engine can’t exhale properly it puts extra pressure on seals and o’rings.

    If this smoke is more of a black color, it could be from fuel dripping into the cylinder and having to burn off causing more of a dark blackish smoke with a raw fuel smell to it. Leaking fuel injectors and or fuel pressure regulator are common causes.

  25. Clifford Strain says:

    Hi, I have a peugeot 207 1.6hdi with 72k miles on it. Each time I start it up, there is a lot of blue smoke and it smells very strong. Its lumpy but after 10 secs it seems to clear

  26. Austin Davis says:

    Thank you very much Felix

  27. Felix L Valenzuela says:

    i’ve red one of many reasons regarding smokes on engine…thank you veru much sir,as it really helps a lot.
    Keep up the good work and may the good Lord bless you,sir.

  28. Austin Davis says:

    I would get a mechanic to read your computer codes and investigate what the code is and why it is coming on. There are MANY sensors and things that can cause this to happen. Black smoke is due to excessive fuel inside the engine, so the engine is “running rich” and can’t burn all that fuel. This should be a pretty easy repair once they diagnose the engine light code.

  29. Janelle says:

    Hi My minivan is a 2005 Chrysler t&c it just had cpu replaced because was sputtering or misfiring. It is a month later and it is doing it again. The engine light is on and the gauge will read it is overheating but the van is not really over heating and then it started misfiring with what looks like black smoke coming out the tail pipe please help no one seems to tell me anything or how to go about checking it.

  30. Austin Davis says:

    Well, you could have antifreeze dripping down into that #4 cylinder due to a head gasket leak inside the engine, or you could just have a problem with that cylinder like a bad spark plug wire, spark plug, fuel injector, or ignition coil.

    I think I would get a mechanic to investigate further the misfire, and if you are low on antifreeze inside the radiator I would also get that mechanic to do a cooling system pressure test to see if you have an internal leak (headgasket) or external leak (water pump or hose etc.)

    if you do have a headgasket leak, let me know I can show you a great alternative to the costly repair

  31. Maria says:

    Hi :) My car started to misfire and then white smoke came out of the tail pipe – along with that my car started to over heat and I thought I could smell antifreeze so I ran a test on my car and the test came back showing that the #4 cylinder has a misfire. I guess what I am wondering is what could this be? My cooling system is leaking perhaps? Any information you could give me would be much appreciated, Thank You so much for taking time to read my letter. Sincerely, Maria :)

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