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Big Clouds of White Smoke and Not Head Gasket!!!

Girlfriends 2000 Honda CRV with 220,000 miles runs great, idles great, shifts great and has plenty of power. Blowing out giant clouds of white smoke while hot or cold. Does not overheat or use any coolant. Is the engine toast. I have to get a smog check in California. Diagnostic check flags 02 sensor. Please help can't afford a car right now.


  • Well, one thing that causes that to happen is a bad head gasket, but you say that is not the case. Another cause would be a broken piston, but you say it runs well. So I don't know.
  • White smoke (when the car is warmed up, not so much when first starting it in cold weather) usually means coolant is getting into the combustion chamber. It doesn't take much, but if tis white smoke has beenn going on for months without coolant loss, I suspect youare right it isn't the head gasket. In that case it must be either water in the gas tank or some kind of air/fuel mixture problem. But water in the gas tank usually causes all sorts of performance problems, so that's unlikely. So it must be an a/f problem. hmmm ... Assuming all routine engine maintenance is up to date (esp the air filter) by the owner's manual schedule and there's no weird engine noises. O2 sensor(s) should be checked first. Hopefully one is broke and fixing it will resolve the problem (although unlikely in my opinion). If O2 sensors are ok, if this were my car, I'd do a compression and leakdown test next. After that, the next possibility is the fuel pressure is off, or the MAF is broken or maybe it needs to be cleaned.
  • Check the brake fluid level in the brake master cylinder.

    The seal in the master cylinder can leak brake fluid into the brake booster. The vacuum hose to the brake booster can then suck the brake fluid from the brake booster into the engine where it burns and causes a white smoke out of the exhaust.

  • edited January 2013
    Is the smoke or steam coming out of the tailpipe or somewhere under the car? Are you losing coolant or any other fluid? What does the smoke smell like? Finally, how do you know it isn't the head gasket? How was this checked?
  • Hondas use alumasil engine blocks with no cylinder liners..The piston rings ride directly on the aluminum cylinder walls..This technology usually works well, but when it fails, massive oil burning results...If you are seeing a LOT of smoke, then ONE of the fluids (motor oil, transmission fluid, coolant, brake fluid) is being consumed at an abnormal rate. By carefully monitoring all the fluid levels, you will find the problem...Synthetic oil can produce white/grey smoke when it burns..
  • What Tester described happened to me and a new master cylinder solved it (different make of car).
  • My older car had a vacuum modulator for trans shifting. Of course your newer honda does not use engine vacuum to control trans shifting. Burned trans fluid in intake.
  • .If you are seeing a LOT of smoke, then ONE of the fluids (motor oil, transmission fluid, coolant, brake fluid)
    How is tranny fluid, or brake fluid getting into the cylinders???

    White smoke is an indicator of water..NOT motor oil or tranny fluid. That would be a blue smoke.

    All my vehicles had white smoke on the cold mornings..but after a few minutes it was gone.
    Synthetic oil can produce white/grey smoke when it burns..
    HOW's that?? Synthetic oil is chemically the same as convention oil with impurities removed. So hows it going to burn differently??
  • I suppose it could be argued that regular oil also produces white/grey smoke when it burns........Now that I've had the cataracts removed in one eye I can clearly see that my color perception was wrong. :-)

    Stove, I popped a leak in the vacuum modulator diaphragm in my ol' '64 Fairlane. Flooring the motor prduced huge clouds of pure white smoke. And knocking....God, did that stuff preignite!

    Caddyman is right. Find out which fluid is being used up prematurely and it'll point to the source of your problem.
  • Back in the day, early Honda alumasil engines were failing prematurely and burning a lot of oil which got them failed during emission tests because of visible smoke..Their owners learned that if they switched to the heaviest grade of Mobil-1 synthetic oil, they could sometimes get past the test because this lubricant produces very little smoke when it burns...What smoke there was was white, not blue....
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