• It often means that you are burning antifreeze. You asked if it needs antifreeze, have you noticed any leaking out of the reservoir tank while you are running it? Sometimes when the head gasket goes it will produce a passage for the antifreeze to pass from the capillaries into the combustion chamber. It is easy to check if you have an air compressor. Remove one of the rear sparkplugs and the radiator cap. Fill the radiator and then push some air into the sparkplug hole (get a good seal in case a valve is open). Repeat with all the cylinders and watch for air bubbles coming up into the radiator. If bubbles come up or fluid is pumped out, the head gasket is blown and must be replaced. It is more likely to happen at the back of the engine because it is farthest away from the fan and therefore gets less cooling. Also check your oil for discoloration. If it is a brownish color it could mean your oil and antifreeze are mixing and has the potential to damage your bearings.

• If the exhaust billows white smoke for a few seconds when first starting the engine after it has been sitting for a while, such as overnight, and then runs normally, it could mean that the rubber valve stem seals have perished - especially if the vehicle is a few years old and has done over 60/70,000 miles. Another clue is: does the exhaust smoke smell like fresh, rather than burnt oil.

• After going nuts trying to figure out sporadic tailpipe smoke on my Nissan Maxima, with no other negative engine symptoms, I eventually stumbled upon a malfunctioning PCV valve. The ball-check wasn't fully seating, allowing small amounts of oil to sneak past and into the combustion chamber. A cheap and easy fix.

• White smoke or semi white can be produced in several ways. One way is oil this is normally a whitish blue to blue smoke and has the apparent smell of oil being burned. Next could be antifreeze when it is being burned it has a sweet type of smell and tends to dissipate in the air rather quickly. Next is automatic transmission fluid which is normally found on automatic transmissions and its normally drawn into an engine thru a vacuum line via a defective transmission modulator valve or some other defective part. Transmission fluid is very apparent and billows out so bad that you can't see anything behind you. Last but not least another type of smoke that is not white but black is the presents of to much gas/fuel being burned in the engine. PS the one good thing about transmission fluid being burned is it is an excellent way to clean the carbon out of an engine.

• Black smoke is burning oil. Blue smoke is usually transmission fluid due to a leaking modulator valve in the older auto transmission. White smoke is due to water getting in to a cylinder from a bad gasket, cracked block or a cracked head. cracked heads. Mine started misfiring, with new plugs. Smoke came out the exhaust. Result, low compression in the cracked head. When car was cold it ran fine. After it got hot, the crack in the head would open up, hence, sputtering. I've had to replace 3 heads. Everytime I've had to have this done, I had to buy a whole new head gasket.

• After extensive research I came to the conclusion that TOO much oil is also a main culprit for white smoke out of the exaust.

• I changed the PVC valve, the breather and the air filter and it's good as new.

• There are a lot of incorrect answers here... but for the most part, you can hold true to these: Blue smoke is primarily from internal engine wear. If it's constant when the engine is on, then the rings etc are worn and need to be replaced. If it only is blue when the engine is cold or first started, the rings are worn but not gone completely. You get the oil seeping during the night and it burns off when the car is started in the morning. Black smoke is a fuel/air mixture suggestion problems with injection or carburation. Cause of black smoke is due to running rich in the fuel air mix. White smoke can and DOES come from coolant burn off in the oil due to a leaking or blown head gasket, cracked head etc. If you aren't sure or you don't know what you're talking about, don't advise. Wrong advice can be more damaging than the actual problem.

• White smoke is caused by engine coolant/Antifreeze being processed in the combustion chamber(s) of the engine.....ie burning, melting, frying, whatever....Period....I'll explain further.... This is automotive chemistry 101....Oil of any automotive type burns blue.....too much fuel issues burn black not enough fuel issues burn grey on a cold day you may see what appears to be white smoke from the exhaust that will disappear after the vehicles engine has warmed up to it's normal operating temp.. This is a normal reaction called condensation... condensation is the result of a small amount of water/dew being drawn into the exhaust usually collecting in the muffler and/or the catalytic converter and is caused by our friend mother nature..... like when you see your breath on a cold day...

• I am a highly experienced ASE certified automotive repair tech. I have over 16 years of diagnostics and repairs to my credit..I have made a very good living in the automotive business by being precise with my diagnostic procedures....I have worked for 3 of the largest rental vehicle companies in the country.... I have diagnosed and repaired an estimated 200 vehicles to date with the white smoke issue... every vehicle that i mentioned had engine coolant/antifreeze entering one of the combustion chambers in the engine... Most of these vehicles had a damaged head gasket(s).. the most common causes of this issue that i have detected over the years are due to improper maintenance of the engine cooling system, severe overheating of the engine, improper tightening of the cylinder head(s) during an engine overhaul,or some other type of repairs that required the head to be removed and also defects in manufacturing of the gasket or the engine... i have seen evidence of careless repair techs that have scratched or cut the surface of a replacement head gasket with either a tool or the cylinder head during the install process.. sometimes it will never cause an issue but it can... i am very careful when dealing with any gaskets but especially head gaskets due to the amount of work involved in replacing one on some vehicles.. bottom line, I'm not fond of doing the job twice so I'm careful the first time... I have seen improper cylinder head or engine block servicing techniques cause failure of the gasket(s) these types of failures are generally caused by improper cleaning of the gasket surface of the engine block and/or the gasket surface of the head.. i have also repaired or replaced cracked heads and in extreme scenarios i have replaced cracked blocks and severely overheated engines with a new or re-manufactured engine due to such severe damage to the internal engine components or block .. There are a mix of correct and incorrect answers to your concerns by the participants that have replied.. I can assure you that almost every well trained tech will answer your questions as i have.. I'm not saying I'm an automotive god, I am just proud of the priceless knowledge that i have acquired...FYI, I'm a graduate of Denver Automotive and Diesel College in Denver Colorado.... DADC is one of only two Automotive Technology colleges in the country with the intense hands-on and classroom teaching practices to properly train a truly, highly skilled automotive/diesel tech who can easily handle any diagnosis and proper repairs of yesteryears and today's automobile technology....

• White smoke CAN be caused from oil....I have fast-road engined 1987 Golf Mk II. If I boot it hard on tight corners, roundabouts, etc, it can cause oil surge in the engine and some oil can 'slop' into a cylinder. The James Bond style smokescreen it produces can be very exciting for drivers behind me!

• Lots of good answers; I just want to see if I can clarify from my experience. SMELL!! Good mechanics without great diagnostic tools learn to SMELL. "Burning" (yes, technically it's boiling, not burning) Antifreeze smells 100% different than burning OIL. Let your nose be your guide. The Antifreeze will have a sweet sort of smell--hey--kinda like antifreeze smells, and it will make your eyes tear up and your throat lungs will tell you to get out of that toxic fog right away. Also--the timing. Yes, when forming a good question, you need to give GOOD DETAILS. Does it ALWAYS burn white? Just at startup? Only when hot? Etc. DESCRIBE, DESCRIBE, DESCRIBE!!! A head gasket problem is ALWAYS there and it only gets worse under pressure/acceleration/load. It will go from a little cloud to it's own weather system when you stomp on the gas.

• OVERFILLING THE OIL will produce this white burned smoke too. Yes, it will SMELL different. IT will also usually go away after some driving. CHECK THE DIPSTICK, it's obvious, but do it--do it right. Flat surface; cold engine. Pull--Wipe it off--put it in--now you are getting the real level. Oil burning will be at startup from worn valve rings/seals and during driving from overfilling at first a lot, then only at heavy acceleration/g forces when demand is high. Again--smell, check all your fluid levels (OIL, WATER, TRANS) of course, whatever is low is what you are BURINING (or for the one gent that gets particular, boiling). ALWAYS Start w the simplest thing or the cheapest. Did you just change the oil and it started--overfilling, etc. Yes, it won't hurt to check the PCV valve and tubing. Really, check all you can check.

• My problem with white smoke was whenever I would be going down the road at high RPM and let off the trottle. Then it was like a smoke bomb went off. Bottom Line.......... My Vacuum Modulator went bad on my transmission whenever high vacuum was created it was sucking transmission fluid into my intake manifold and thus into my combustion chamber creating white smoke. Replaced the modulator for $12 and everything is right with the world

• i had the exact problem with my Mazda down to a T. All we had to do was buy a bottle of engine sealant... it takes a full day to run thru so follow directions exactly. Now the car has no problems... full power is bacl no more "smoke bombs" and no more dying at strange times.

• Steam or smoke is the question here. If its steam some considerations are what year is the vehicle newer catalytic converted cars emit steam and water from the exhaust and you should be cautious about the blown head gasket or cracked head syndrome, if you suspect a blown head gasket or cracked head go to a reputable shop that can confirm exhaust gasses in the coolant. You will notice a low coolant level and a peanut butter looking substance on the oil cap (possible traces of water and coolant in the oil but generally engine pressures will prevent this. Be prepared for the worst and hope for the best. If it is smoke a thick white smoke it could be transmission fluid being pulled up through a vacuum line to the intake manifold and being burned, this was quite common on older Ford and Chrysler vehicles that had a vacuum shift solenoid and an automatic transmission.

• Has your car severely overheated recently? Does the smoke smell like antifreeze? If it does, you probably have a blown head gasket. The "smoke" in this case is actually steam from water leaking into the cylinders. Also check for yellow or white goo on the oil cap and dipstick, indicating water leaks to the oil.

• Your symptoms are indicating a possible head gasket problem. You have water going into the combustion chamber and coming out the back tailpipe as steam. You may also have exhaust gas in the water which can also be checked by a mechanic. Be prepared for the expense of a head gasket or possible engine replacement.

• If it is not happening all of the time at operating temperature (head gasket as mentioned before) and it occurs just at startup. It may be that due to heavy moisture in the air, dew, a heavy rain, will build up moisture in your exhaust system. At initial startup until the vehicle is warmed up and run for a bit, you may see thick white smoke.

• I had an old engine that sucked oil through an intake valve when the engine went fast enough. If you burn enough oil it looks white. Especially in Michigan on a cold morning.

• I had this problem with my '96 Ram after an overheat. A cracked head gasket was allowing antifreeze to get into the combustion chamber and creating all kinds of white 'sweet smelling' smoke.

• White "smoke" in cold weather is just steam. When gasoline ignites it produces quite a bit of heat and expands to several times the original size, creating high pressure on the piston. That pressure causes the piston to move down, turning the crankshaft which makes the car go. When the fuel ignites it causes a sudden and violent chemical reaction between the the oxygen in the air and gasoline (which is a long chemical molecular chain of carbon and hydrogen) resulting in carbon dioxide and water vapor. As the water vapor cools in the exhaust pipe it starts to form small droplets that are visible in the form of steam vapor. That's the white smoke. Once the exhaust pipe warms up sufficiently, the exhaust leaving the pipe is still hot enough that the water vapor hasn't formed the droplets and dissipates quickly enough that you don't see the vapor. On the other hand, if it's light blue or blue-grey smoke and it doesn't stop when the exhaust pipe warms up, that's oil vapor and a sign of bad rings and/or valve stem seals.

• white smoke is usually caused by condensation in the combustion chambers. This will usually dissipate once the car has warmed up. If it persists there could be difficulties with: Problem: Solution: Moisture in fuel Apply one cap full of Methylated spirits to fuel tank (This is quiter safe by the way, it dissipates water) Head gasket leak Replace head gasket, approx $500 AUS (other symptoms such high temperature will also be prevailent.) Failing these two suggestions, there is a slight chance of moisture in the oil sump. this is rare if the head gasket is ok. Simply check your oil level, if the oil looks milky, there's the problem. Also if it is milky, replace the head gasket.

• Your engine would smoke if you are running at too high RPM or have had your RPM at a high level before. The engine is getting overheated. When you say it only smokes until about one mile it sounds like a problem with the engine. starter.

• I would guess that its parents probably did and it learned it from its environment. More realistically, is it white smoke you see? And I would further guess that you have a 3.8 motor. If this is true, plan on a head gasket job and shave the heads. $1200 to $1400 if a shop does it. Or stress, frustration and possibly as much if you do it and it doesn't go well!

• I doubt it's the starter. You probably have bad valve guides. Oil slowly runs down your valves after the engine is off then burns away as you drive. It stops after a mile because oil pressure keeps them sealed. If you had bad rings it would always smoke or always some when you decelerate at high speeds. Closing the throttle at high speed created high vacuum in the motor and suck oil up past the rings into the combustion chamber where it burns.

• One or more oil rings are bad.

• Valve seals become brittle and need replaced at about 100,000, sooner in hot climates. Rings will also make it smoke, or raw gaz puddling in the intake manifold if carburetted, excessive crankcase pressure will force oil past the rings if the system does not have relief through the pcv valve.

• Unfortunately--That 1st answer is BAD (in this case). Overheating right at start up--Hey--On Planet Earth, engines don't overheat right at start up. Of course, physics and your temp gauge will confirm this fact. The too high RPM isn't too bad, but again, not the answer. I'm sure it smokes at low/high idle until warm. BINGO--The VALVE guys all have the right answer, in my opinion. There are other reasons it might smoke, as given, even overfilling; but from your description, it's the valve seals! They smoke when cold on start up then go away. It will get worse and worse. Budget about $400 from a mechanic that charges merciful rates.

• First of all, the only Correct answer to your question is that your valve seals/Guides need to be replaced.Oil is leaking down the valves when the engine is cold and dripping into the cylinders, thus burning off after the first mile you drive.As your engine warms up and the oil burns off, the smoke will disappear. You will have this problem after your car is sitting for a while or on cold starts. Just for knowledge, Blue smoke is burning oil. Black smoke means over fuelling or air restriction whih means to much fuel. White smoke means burning antifreeze or water which is caused by a bad head gasket. By the way, the first two answers to your questions are completely out to lunch, These people have no business answering automotive questions.

• I have a truck that does the same thing. It recently passed a CA smog test despite the huge amounts of smoke it puts out after first starting. The smoke is white but I can imagine someone describing this as "blue". The obvious reason it is smoking only after it starts was stated by the guy who said valve guide seals. Oil is pumped up to the top of the cylinder head above the valves and cylinder pressure (not oil pressure) keeps the oil from flowing down into the cylinder. When you turn the motor off it runs down into the cylinder. When you go to start it the oil burns up and comes out as smoke. My car also diesels and back fires when I shut it off. It does not run very well on oil but it will run for a while. This will cause your plugs to foul early and you will burn more oil than usual. The repair requires removal of the cylinder heads...usually. That's my 2 cents worth. The other answers are incorrect and are not even close. I admit I could be wrong but I know it's a pretty good guess...it seems several others here have the same opinion.

• I had a Mazda that lost power and would smoke a blueish whitish smoke and later started to die. Turned out a bottle of engine sealant did the trick.

• Additionally, the thumb rule is that: white smoke is usually caused by coolant water (or antifreeze) entering the combustion chamber; blue smoke is essentially due to oil (lubricants) getting in to the cylinder; and black smoke is generally because there is too much fuel (Diesel / Petrol) being inducted / injected in to the engine. And grey smoke would be due to a mixture of water and (excess) fuel entering in to the combustion chamber.

Assume you mean that it's burning oil. Typically that's because of poor maintenance or abuse.

• There are several reasons that an engine will burn oil and most of the time these are caused by inadequate oil changes:
• poor piston ring seal (cylinder taper, worn rings and/or carbon deposits in the piston ring grooves.)
• Worn or faulty valve guide stems
• SOMETIMES bad rod bearing can cause pistons to vibrate, allowing too much oil to remain on the cylinder walls.
• A cracked piston can also cause quite a bit of oil burning, but that's quite rare.

Also

White smoke indicates coolant entering the combustion chamber. Normally caused by a blown head gasket or cracked head. Blue smoke is oil burning, and black smoke is an overly rich fuel/air mixture.

Note that if coolant is entering the combustion chamber there will be other indicators, such as serious misfiring and/or coolant will be blown from the water jacket. Without those indicators you are probably not getting water in the combustion chamber

Check your oil,- is it foamy?

Examine your coolant. Does it smell like oil?

Is the smoke sweet smelling?

Knocking has nothing to do with a head gasket, sounds like you have multiple engine issues to me.

And finally...if changing a head gasket is simple, why does it cost so much? because if you don't work on cars all the time it is most definitely not simple and includes timing belt removal usually.

Overheating can cause knocking. then refer to the above....

Your best bet is to replace your motor because usually the knocking noise is caused by a spun bearing which would cost a lot to repair.

*** New Below ***

The white smoke is from a blown headgasket, your coolant is leaking into one or more cylinders and that's actually steam that you see coming from your tailpipe.

When this happens, your coolant level drops (because it's pumping it out the tailpipe), your car overheats, and of course it will knock as it overheats. An overheated car is sluggish, as well.

Another bad thing that occurs by driving a car with this problem is that the coolant is washing the oil off your cylinder walls and your rings will tear up your cylinder walls as they self-destruct.

Head gasket replacement is not an easy fix nor is it cheap, and usually you'll need to get the head machined to make it perfectly straight again - heads warp from overheating. A good mechanic can do a head gasket replacement in a few hours.

- Dazani

This soudns like engine failure. Probably blew head gasket and ruined the engine due to it being run with bad head gasket too long.

You can find a god used engine with lower miles for around 800 at the most. usually more around 500 or 600 at most yards if you call around.

Labor to replace an engine we charge about 300 to 400 usually.

The car may not be worth doing this with however, some are not.

Most are though, if clean straight and drove fine.

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If your vehicle has a Diesel engine, then you may just be looking at 'fuel starvation'! All of the above are to a degree correct - but unlike Petrol engines, Diesel engines are also known to emit white smoke through the exhaust system when fuel delivery to the cylinders is restricted and give off the same appearance as a head-gasket problem.

This could also cause 'sluggishness' or lack of power, bad starting or non-starting and also a low type knocking noise.

Change the filter and check that the fuel lines are not clogged or restricted; you could even possibly run your own fuel supply line from a can to check this part out if it's easier for you!

Start the engine and rev it at about 3,000 rpm for a few minutes or take it for a short drive to see if it still loses power, if it still does then assuming all has been changed and cleaned, you might look to see if there is something in the fuel tank that could be blocking the supply pipe!

Perhaps this may help you in your search for causes. A high hydrocarbon reading is usually unburnt fuel. If the CO reading and the NOx readings are below the limit then look towards an ignition problem as being the most likely culprit. As the prior answer suggested, start checking items and begin with the basics. Year, make model, engine size, options, symptoms etc will help you get a more accurate answer next time.

Check the plugs first, all of them! One bad plug will give you a miss and everytime the car misfires unburnt gas goes into the cylinder and out the exhaust which raises the HC. Same goes for the wires (check resistance with a multimeter) check the distributor cap & rotor (if applicable) for cracks, corrosion or burnt areas. Might want to do an injector service (if applicable), a sticky injector might put fuel in at times when its not supposed to and up goes the HC. If the check engine light is on 1st thing to do is pull some codes and this will give you some direction. Codes can be pulled manually by using the diagnostic connector or a scanner.

Answer

High hydrocarbon levels are also seen with a much too lean mixture. If you are looking at an older carburated car, check this first. A lean mixture will not burn completely, and unburned mix goed out the tailpipe. An overly rich mixture burns fine, but to carbon monoxide, not dioxide. So a rich mixture will fail on CO, not HC. This is the reason for the vacuum hose fix - it cuts down the amount of air entering the engine, while leaving the fuel the same ( or increasing it a little if the leaks are really bad ). This said, the ignition system is also suspect, as any misfire will increase HC. So, check your vacuum hoses (lightly spray connections w/ carb cleaner, an RPM increase means a leak), change your plugs and wires if they're more than a year old, and richen the mixture a hair if this adjustment is available.

More Information:

I had to replace a lot of vacume lines to get mine to pass. It also could be o2 sensor, bad spark plugs, rich idle(too much gas), bad spark plug wires, bad injectors(or carburetor), bad ignition coil/cap/rotor(weak spark), bad catalytic converter/clogged muffler, exhaust leak, etc.

If you are having a lot of white smoke all the time the car runs then check for coolant mixing in with the oil,look for water in the oil when you check the oil or milky brown oil. This produces a white "steam" that is very thick to come out of the exhaust. If your engine temp. gauge is very high and over heats you probably have a blown head gasket. If it has a bluish tint look it may be burning oil. Indications might be how much oil is currently in the car i.e too much oil, or if there is a leak in the line you may be adding a bunch of oil over a short time. If it is only when you first start the car and the engine is cold, then it may be that your valve seals are bad and need replacing. Hope this might help or at least give you some ideas...