Exhaust smoke, black vs white?

samzheresamzhere BannedPosts: 10,923 Senior Member
My girlfriend's nephew -- he lives near here -- has some white smoke coming out his exhaust.

His car is an older 90s Ford Mercury. This is his 2nd car and he owns a newer pickup too.

He called her last night about the white smoke and I told him to check his radiator water, and sure enough, it was down somewhat.

I told him to carefully watch the temp gauge, keep the radiator full, and to not drive his car much, and to get it to his car repair folks today.

I'm pretty clueless about car problems but I do think I remember that if you're pumping smoke out of the exhaust, the color of the smoke is a clue.

White smoke usually indicates that you're vaporizing water, and that maybe you've got a cracked head gasket and that water from the cooling jacket is mixing into the exhaust manifold. And that dark or blue smoke indicates that you're burning oil.

Am I correct on this? Thanks in advance.

Outside of a dog, a book is a man’s best friend. Inside of a dog, it’s too dark to read. - Groucho Marx

Replies

  • Big Al1Big Al1 Senior Member Posts: 7,052 Senior Member
    I think that means they selected a new Pope!!
  • TeachTeach Senior Member Posts: 18,429 Senior Member
    Black smoke- - - - - -rich mixture, flooding, etc.
    Blue smoke - - - - - -oil burning, bad piston rings, loose valve guides, PCV valve stuck open, etc.
    White smoke- - - - -coolant in the combustion chambers, blown head gasket, cracked cylinder head, etc.
    White smoke with a choking odor- - - - -brake fluid being drawn into the intake through the master cylinder booster. Engine usually runs rough and brakes go away quickly due to fluid loss.

    There will be a test after the lecture- - - - -pay attention!
    Jerry
    Hide and wail in terror, Eloi- - - -We Morlocks are on the hunt!
    ASK-HOLE Someone who asks for advice and always does something opposite
  • breamfisherbreamfisher Senior Member Posts: 13,112 Senior Member
    I'd add: does the white smoke disappear, or is it only at startup? I've known a few folks who have "white smoke" at startup that's just condensation in the exhaust system being cooked off as everything gets up to to temperature.
    Overkill is underrated.
  • samzheresamzhere Banned Posts: 10,923 Senior Member
    Big Al1 wrote: »
    I think that means they selected a new Pope!!

    Now that's a good one! Rimshot!

    Outside of a dog, a book is a man’s best friend. Inside of a dog, it’s too dark to read. - Groucho Marx
  • samzheresamzhere Banned Posts: 10,923 Senior Member
    Thanks Teach! Smoke wasn't choking so maybe my guess was correct, likely he's blown a head gasket.

    Will report later when we hear back from the nephew.

    Outside of a dog, a book is a man’s best friend. Inside of a dog, it’s too dark to read. - Groucho Marx
  • Big Al1Big Al1 Senior Member Posts: 7,052 Senior Member
    samzhere wrote: »
    Now that's a good one! Rimshot!

    I'll be here all week and don't forget to tip your waitress!!
  • TeachTeach Senior Member Posts: 18,429 Senior Member
    If it's got a pretty serious coolant leak, the first start in the morning will be difficult, with a noticeable miss and lots of white smoke. This is caused by coolant in the engine being burned away after sitting overnight with coolant accumulating in the combustion chambers.
    Jerry
    Hide and wail in terror, Eloi- - - -We Morlocks are on the hunt!
    ASK-HOLE Someone who asks for advice and always does something opposite
  • PFDPFD Senior Member Posts: 1,202 Senior Member
    Don't some cars have a diaphragm in the **** control valve that is regulated by vacuum?
    If this leaks then ATF can be sucked into the intake manifold and you look like James Bond trying to give the bad guys a smoke screen.
    That's all I got.

    Paul
  • TeachTeach Senior Member Posts: 18,429 Senior Member
    Transmission modulators are much more likely to develop a seep leak than a total failure of the diaphragm. That causes a slow loss of ATF without a lot of noticeable smoke. A sudden total failure of the modulator usually results in very high-RPM shift points and big clouds of smoke.
    Jerry
    Hide and wail in terror, Eloi- - - -We Morlocks are on the hunt!
    ASK-HOLE Someone who asks for advice and always does something opposite
  • samzheresamzhere Banned Posts: 10,923 Senior Member
    Teach and others...

    Latest word is that there's a faulty valve seal.

    Does that make sense? And... what sort of money is he looking at for such a fix? That's assuming he goes ahead and does the fix instead of junking the engine.

    Any general ideas regarding relative costs for such? Thanks.

    Outside of a dog, a book is a man’s best friend. Inside of a dog, it’s too dark to read. - Groucho Marx
  • timctimc Senior Member Posts: 6,684 Senior Member
    Older vehicle, automatic transmission, can be caused by bad modulator valve on the transmission sucking transmission fluid into the engine.
    timc - formerly known as timc on the last G&A forum and timc on the G&A forum before that and the G&A forum before that.....
    AKA: Former Founding Member
  • LMLarsenLMLarsen Senior Member Posts: 8,337 Senior Member
    Another FYI: burning coolant smells like burning maple syrup.
    “A gun is a tool, no better or no worse than any other tool: an axe, a shovel or anything. A gun is as good or as bad as the man using it. Remember that.”

    NRA Endowment Member
  • Big Al1Big Al1 Senior Member Posts: 7,052 Senior Member
    samzhere wrote: »
    Teach and others...

    Latest word is that there's a faulty valve seal.

    Does that make sense? And... what sort of money is he looking at for such a fix? That's assuming he goes ahead and does the fix instead of junking the engine.

    Any general ideas regarding relative costs for such? Thanks.

    http://www.bing.com/videos/search?q=monkey+joke+penguin&qpvt=monkey+joke+penguin&FORM=VDRE#view=detail&mid=B7EB5DB9C1C8D9E4DB8BB7EB5DB9C1C8D9E4DB8B
  • tennmiketennmike Senior Member Posts: 26,106 Senior Member
    Rebuilt heads don't cost a lot; having them installed does.
    If the U.S. Congress was put in charge of the Sahara Desert, there would be a shortage of sand in under six months.



  • JLDickmonJLDickmon Senior Member Posts: 1,726 Senior Member
    transmissions haven't had modulators in years.. been electronically shifted for a decade..
    Never laugh at your wife's choices.
    You are one of them.
  • samzheresamzhere Banned Posts: 10,923 Senior Member
    cpj wrote: »
    That means a head rebuild, I believe. Which translates to lots of Benjamin's. I'm guessing about 10 of them.

    That's kinda what I thought, if the upper is shot, head gasket or valve or whatever, an upper rebuild is likely necessary.

    But latest news...

    The nephew took his car to a mechanic who told him that the problem was that he's been using synlubes (synthetic oil) -- and he has been using the premium synlubes, true -- but that the white smoke is due to the use of these lubes and if he switches to conventional lube, all will be okay.

    At point which I simply said, "Mmm, okay." and offered no further opinion. I've never heard anything about synthetic lubes being detrimental to an engine before this. Maybe an unnecessary expense, yes. But harmful or causing problems otherwise? Nope.

    Any ideas on this? I kinda backed off and stayed out of the issue, as I'm certainly no eggspert on motors. Huh.

    Outside of a dog, a book is a man’s best friend. Inside of a dog, it’s too dark to read. - Groucho Marx
  • timctimc Senior Member Posts: 6,684 Senior Member
    JLDickmon wrote: »
    transmissions haven't had modulators in years.. been electronically shifted for a decade..

    As I said, if its an older vehicle, maybe so; Sam said 90's so that could be up to be 25 years ago....not sure if it was late 80's or early 90's when they quit using them. By the way that's 2.5 decades ago!
    timc - formerly known as timc on the last G&A forum and timc on the G&A forum before that and the G&A forum before that.....
    AKA: Former Founding Member
  • JKPJKP Senior Member Posts: 1,838 Senior Member
    Caused by synthetic oil sounds like BS to me....
  • TeachTeach Senior Member Posts: 18,429 Senior Member
    Send some of that BS you're getting my way- - - -gotta get the garden ready for next spring! Valve guide seal problems won't cause coolant loss, so unless it was low on coolant as a coincidence, look for another mechanic. Ditto on the synthetic lube. Using synlube is a fool's mission on an older car- - - -twice the cost for no benefit, but some people insist on it.

    Here's the diagnostic procedure I would use:

    1. Is the car overheating?

    Yes: Do a cooling system pressure test to see if the coolant leak can be located. Possible sources- - -blown head gasket, cracked cylinder head, external leaks like water pump, rotten hoses, etc. By the time the overheating gets severe, a high-mileage engine is probably trash. Trade the car.

    No: Look for other sources of smoke. Head gaskets and other cooling-related problems are unlikely.

    2. Does the smoke happen only on a cold start, or after the engine has been idle for several hours?

    Yes: Now a valve guide and/or guide seal is a possibility, and some guide seals can be changed without removing the cylinder heads. Swapping guide seals only is a short term fix. The seal wore out because the valve guide is sloppy and the valve is flopping around in the seal.

    No, the smoke is there every time the engine is started, or smoke is constant with the engine running: Worn out piston rings- - -probably uses lots of oil between changes. This one requires a special repair procedure. Put a nickel in the ash tray. Drive the car into the nearest deep body of water. If anybody fishes it out, they don't get a total loss- - - - -they get a nickel!
    :jester:
    Jerry
    Hide and wail in terror, Eloi- - - -We Morlocks are on the hunt!
    ASK-HOLE Someone who asks for advice and always does something opposite
  • samzheresamzhere Banned Posts: 10,923 Senior Member
    Thanks, Teach, I'll check w. the nephew.

    Incidentally, the car is a '95 Merc Grand Marquis, and its body and interior are cherry.

    Outside of a dog, a book is a man’s best friend. Inside of a dog, it’s too dark to read. - Groucho Marx
  • PFDPFD Senior Member Posts: 1,202 Senior Member
    Sam, maybe try some "high mileage" oil at the next change.

    I believe it has some sort of "seal swell" additive.

    I wonder what Teach thinks?
    That's all I got.

    Paul
  • BufordBuford Senior Member Posts: 6,661 Senior Member
    Hope in a can.
    Just look at the flowers Lizzie, just look at the flowers.
  • sarg1csarg1c Senior Member Posts: 1,707 Senior Member
    Teach wrote: »
    Black smoke- - - - - -rich mixture, flooding, etc.
    Blue smoke - - - - - -oil burning, bad piston rings, loose valve guides, PCV valve stuck open, etc.
    White smoke- - - - -coolant in the combustion chambers, blown head gasket, cracked cylinder head, etc.
    White smoke with a choking odor- - - - -brake fluid being drawn into the intake through the master cylinder booster. Engine usually runs rough and brakes go away quickly due to fluid loss.

    There will be a test after the lecture- - - - -pay attention!


    Jerry

    no smoke but foul odor:too many beans and cabbage....
  • TeachTeach Senior Member Posts: 18,429 Senior Member
    Buford wrote: »
    Hope in a can.

    :that:

    Kinda like 9-1-1- - - -government sponsored dial-a-prayer! If that car has the 4.6 liter overhead cam V-8, a valve job/oil seal replacement is a huge P I T A. Just getting the cylinder heads off the engine is a major hassle and most shops prefer to remove the engine rather than do a head swap with the engine in the car. If it's got the older 5 liter pushrod V8 a valve seal swap can be done in the car, without removing the heads. Unless the guy is willing to spend around $2K on a valve job, which is about what the car is worth, he can either get accustomed to leaving a trail of smoke, put a little insecticide in the oil and fog for mosquitoes, or dose it up with 2 or 3 cans of STP to minimize the smoking temporarily and trade it off.
    Jerry
    Hide and wail in terror, Eloi- - - -We Morlocks are on the hunt!
    ASK-HOLE Someone who asks for advice and always does something opposite
  • snake284snake284 Senior Member Posts: 21,857 Senior Member
    I'd add: does the white smoke disappear, or is it only at startup? I've known a few folks who have "white smoke" at startup that's just condensation in the exhaust system being cooked off as everything gets up to to temperature.

    This can also do this with the blue smoke because of valve guides. I overhauled a 350 Chevy. after the overhaul that engine would diesel on me when I shut it down and it was burning a quart every thousand miles. I put up with it hoping against hope that maybe a ring wasn't seated yet and would eventually lap in and slow down or stop the oil burning but it didn't so after a few months I pulled the heads and took em to an old school mate of mine that had a garage and machine shop. He nurlized the guides a(I was too cheap in those days to have bronze guides installed and Nurlizing worked pretty good)and put on a fresh set of the Perfect Circle seals and it stopped all that B.S. Those rings had been seated from the first few hundred RPMs just like Chrome Moly rings are supposed to.

    Anyway, the point of this story is that before I had the guides nurlized when I cranked it up after sitting all night I got a brief blue gray cloud because the oil would run down the valve guides into the combustion chambers while it sat there. That's why I suspected the guides in the first place.
    Those old Perfect Circle seals were good but they weren't a cure all if the guides were worn excessively.
    Daddy, what's an enabler?
    Son that's somebody with nothing to do with his time but keep me in trouble with mom.
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