Home / Auto News / News article: What Does the Smoke from My Exhaust Mean? - AutoGuide.com News
 |  Jan 31 2013, 12:01 PM

If you see different colored exhaust fumes it’s time to pay attention to your car. Even if your vehicle isn’t flashing any warning lights, the smoke coming from your exhaust is a signal that something might not be working properly.

What does BLUE smoke from my exhaust mean?

If your car is blowing blue smoke, it’s a clear sign that the engine is burning oil. What happens is that the valve guide seals or piston rings are worn out, and oil is leaking past from where it should be lubricating the moving parts, to the combustion chamber where it’s being burned up with the fuel.

If you’re seeing this kind of smoke, check your oil regularly and watch for consumption issues. While an issue that normally should require immediate attention and expensive repairs, including some internal replacement parts, if you’re vehicle is old and the leak is minimal, it can be carefully managed by topping up the oil on a regular basis.

Along with environmental damage, burning oil can cause rough starts, as the process can ruin the car’s spark plugs.

There is another reason for blue smoke, and that’s if the car is turbocharged; the smoke being a sign that the blower is in need of rebuilding or replacement.

What does GRAY smoke from my exhaust mean?

Gray smoke is hard to diagnose directly. Like blue smoke, it can mean that the car is burning oil or suffering from a bad turbocharger. Take the same precautions as with blue smoke, and check for excessive oil consumption.

Gray smoke can also be an issue with your automatic transmission fluid getting burned up in the engine. A faulty transmission vacuum modulator would be the culprit in this situation, leading to transmission fluid getting sucked into the engine and getting burned up.

Furthermore, gray smoke could mean a stuck PCV valve. The PCV system (Positive Crankcase Ventilation) cuts down on harmful emissions by recycling them back into the combustion chamber. However, when the PCV valve gets stuck, pressure can build and lead to oil leaks. Fortunately, PCV valves aren’t expensive, and can be a quick job for a mechanic or a do-it-yourselfer.

What does WHITE smoke from my exhaust mean?

White smoke can be nothing to be concerned about if it’s thin, like vapor. This is probably the result of normal condensation buildup inside the exhaust system. This kind of smoke disappears quickly.

However, thicker smoke is a big problem, and can be caused the engine burning coolant. This can be the result of a serious issue like a blown head gasket, a damaged cylinder head, or a cracked engine block – all of which are costly repairs.

Don’t ignore it, however, as the problem could become far worse. Even a small leak in the coolant can lead to overheating and serious risk of damage to the engine. A coolant leak can also mix with oil and cause serious headaches for you and your car.

What does BLACK smoke from my exhaust mean?

Black exhaust smoke means the engine is burning too much fuel. The first think you should check is your air-filter and other intake components like sensors, fuel injectors and the fuel-pressure regulator. Other reasons could be a clogged fuel return line. Black smoke is usually the easiest issue to diagnose and fix, but burning unnecessary fuel will definitely affect your fuel economy, so don’t think of avoiding this one to save money, it won’t work.

Any smoke coming from your car’s exhaust pipe is a sign that your car is in distress. Pay attention to what it needs to ensure more miles for your vehicle.

  • Robert Buchanan2

    Surely the white smoke you are describing is steam, this should be easy recognised as it will quickly dissapear.
    However if we are talking diesel engines only this would indicate unburnt fuel, an inspection of the fuel injection system should be undertaken including the timing.
    Diesel Bob

  • http://www.lubedealer.com/hiebert rhiebert

    I’ve used synthetic for more than twenty years and seldom see any exhaust that concerns me. The first few minutes the most I see is steam for a few minutes but by the time I get to the first light, there’s nothing to see coming from the exhaust. A neighbor who uses synthetic 2-cycle in his scooter also has a similar experience.

  • Brian Green

    can any one tell me how to remove the rear window louvres on a mercedes 280 SLC R107 1981 model  

  • http://profile.yahoo.com/BCHLGRVGSXAOFGV5NAGC6MRXHU Gordo

    This much is true, synthetic oil may not produce any color if burned but that “colorless smoke” can also hide the fact that your valves or piston rings are damaged. 
    I have used it in 2-cycle motors back when I owned a dirt bike. The advantage was that the residue did not produce a blue cloud and was considerably more green in its use.
     But like stated about, synthetic is not a miracle oil, It cannot “heal” normal wear of those parts that will wear with use anyway.

  • Step I

    My car is not overheating I just bought two weeks its was driving so nice about driving for twenty mins today I felt the driving weird so I pulled over lift the hood and nothing I got home turn the car off turned it back on white smoke a thin layer started to come out what could this be the oil is very old and the radiator had brown water

  • Angel Walker

    Hi I have a 1996 Merc sprinter diesel van has started blowing a bit of white smoke on acceleration esp up hills I recently did an oil change any advice thanks.
    Angel.

  • Jim B

    Have a chevy avalanche and it started smoking when I start vehicle. Seems to quit after running for about 10 seconds and does not smoke when I accelerate! truck has 142,000 miles and uses about a quart between oil changes of 3500 miles. Any suggestions?

  • Chris

    How you doing mate.i only have black smoke comming out the exhaust when I put the foot dwn.i had a problem the other week when the engine started to overheat now this is happening any ideas whats up its a turbo diesel

  • Steven

    Nothing’s wrong with it if its a diesel it’s called rolling coal just don’t lay it to the floor

  • Kristine

    My van is leaking oil and I have black smoke coming from exhaust. It was just a little bit and now it is ALOT. There is no knock in the engine or anything…

  • Randy

    changed my 99 s10 4 cyl manual, fuel pump 3 x this month, vehicle getting gas, but will not start. It will crank but will not start.

  • jimi

    I have a 02 Mustang GT 4.6, when driving it drives fine, but at a stand still it idles really low. and if u just let it idle for like 5 minutes and then rev it, it will blow out smoke.

  • raza manaz

    Low/rough idle when stopped is frequently caused by a dirty throttle body. With your engine turned off and cool, remove your rubber/plastic air intake duct from your throttle body. Then use a can of throttle body cleaner and a couple rags to clean both sides of the throttle body’s moveable throttle plate to remove the carbon deposits that are a normal byproduct of combustion. DO NOT remove the throttle body from the engine because you’re only concerned with removing deposits from the edges of the moveable throttle plate and the adjacent sections of the throttle body throat. Also DO NOT use a wire brush as doing so risks removing a protective finish found on many Ford throttle bodies… if needed, just use an old toothbrush. After you reassemble everything, the engine might start roughly and you might temporarily have a check engine due to excess cleaner remaining within the intake manifold but otherwise your idle should be improved.

  • djbchill

    Can the air conditioner cause normal condensation build up in the exhaust which causes white smoke to come from the tail pipe. I have a Jeep Cherokee.

  • jim

    can anyone tell me why my 91 chev blazer with a 4.3 throttle body is blown lots of black smoke from the exhaust,and at an idle aswell

  • Timothy

    hello to anyone who can help i own a 1998 mustang gt 4.6 and im blowin smoke out the tail pipe both tailpipes that is and its not black and its not blue its like a fog lookin colour if that makes sense can someone please help me out need this car to last a good while

  • AGuest

    White smoke can also mean a gas leak where it shouldn’t be leaking, and a very costly repair.

  • Nishan Amaratunga

    I have an Nissan QG 15 DE 1497 cc engine
    It has a very strange issue
    when i drive through the motorway at a constant speed over 80 km/h it suddenly starts emitting grey smoke..which is very smelly.. afterwards i can raise up the RPM it continues to give smoke
    The timing also gets advanced and the i hear the ignition knock…Can anyone of you give me any opinion about what to do

  • tracey

    I have a 04 volk wagon passit and its has a cloud of white smoke when I drive and the oil light comes on and the car reads oil pressure and it shakes really bad can sum1 please tell me what they think it is…

  • Guest

    same problem as JimB whats the solution

  • Tyler Robillard

    I have a 90 Gmc Sierra with the 350 i bought the truck used last friday and just went and got the oil changed…… right after i left from getting the oil changed it started to blow white smoke…. its only when i put my foot into the accelerator and when im idling is when i notice it…… can someone please inform me a bit on this….

  • Vince

    Have a 06 turbo scion tc noticed white smoke from exhaust. Seen their was oil in exhaust pipe check the oil there was no oil in the engine. Any indication what this may be?

  • ford ranger girl

    I have a 2000 ford ranger xl and we have replaced o2, fuel filter, battery, camshaft position sensor, and plugs, was starting but you had to hold down the gas petal and turn the ignition, then once got started had a bad gas smell, then was at the stop sing and a big fog of black smoke came up then it would not start is the engine or something else. very frustrated with it because I bought it last year.

  • Phillip Cooper

    Yeah. Time for a new engine.

  • Lee

    I have a 07 plate Mazda 6 TDI.The car drives without problem no lights on the dashboard but has white smoke bellowing out of the exhaust.I have been told it is the turbo but I still have the power.Can anyone help?

  • Cyb

    I have an 89 model Mitsubishi pajero and have been using this without any problem but recently black smoke started to show, the mechanic says it is problem with the carburetor and when I showed it to the carburetor mechanic he says it Is because of the old vehicle or carburetor should be changed. I actually don’t trust the carburetor mechanic maybe he wants us to get rid of the vehicle and sell it to him. Can u please give a convincing reply ?

  • Mark

    I own a 2002 pontiac firebird v8 ls1 5.7l daily driver for me and drives great but all of the sudden I went to the store and when leaving it started really rough low idle and it sort of died out/shut of on me. Went to start it and no start, so I let it sit for a couple min and tried again and it wanted to crank so I gave a little throttle and it started but blew out a cloud of smoke, only from driver side tailpipe tho (weird) but it made me a bit nervous so I turned it off and then my dad went to start it again and it wouldn’t start now?? Is there any advice for my situation? Thanks.

  • Nik

    Ur running lean, check intake gasket and TB gasket

  • Nik

    This means too much air and not enough fuel. Check MAF sensor, try cleaning it and cleaning throttle body. Do it yourself it’s easy with some vids

  • Nik

    If it’s on one side then it’s probs the intake gasket on that side. Easy fix

  • cassius

    I have a 89 chevy caprice that blows out white smoke from the tail,And its idle to high what should i do?

  • baberham

    I have a Mitsubishi Endeavor 2004. It sat outside for the last 2 days while I had my garage sale. When I went to start it today, it wouldn’t start. When I finally got it to start, it made a horrible sound ( the type of sound your car makes when it’s already started & you turn the key to start) and then a lot of bluish white smoke came from the tail pipe. It eventually went away and drove fine ( I just drove a couple blocks to grab my garage sale signs). Any clues what might be happening? Also! On Wednesday last week I turned into a driveway to turn around. When I put my car in reverse & began to press the gas , it died but started back up quickly. I did fill it with gas that day also at a place I’ve never filled up at. Need help! I take very good care of my car. I change the oil every 3000 miles also…. HELP

  • dennis

    I start the car no power and black smoke in tailpipe after warm run good

  • Helen

    I have a 1997 camry LE 6 i had white smoke coming from the tailpipe, I took it in for
    what ever was causing the problem and $ 2. 307.03 of suppose repairs I still have
    the same problem.

  • baig

    I have hyundai elantra gls A/T 2013 model. When I push hard the gas at full and instant, car RPM reaches up to 5K rpm and think white smoke came out from tailpipe. I checked all fluids and they were all level correctly. Is this the sign of damage engine?
    When I replaced the engine oil, smoke gone…. kindly advise me for any necessary action…..