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How can I tell why smoke from exhaust?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Neil, Jul 23, 2001.

  1. Neil

    Neil 1/2 ton status

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    is there a way to tell if it is valves or rings without cracking my 400sb open? It smokes almost all the time, more when firing it up in the mornin and idling after it warms up. The smoke is light blue almost white. I know a rebuild is coming soon. It is inevitable, but I was wondering about this smoke deal..

    Neil H.. Alabama.. '78 K5 400ci 4x4 AT,AC,PW Cheyenne. '74 C10 3spd/floor 250ci 4x2
     
  2. denver75k5

    denver75k5 1/2 ton status

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    unless i am mistaken, If it's the valves it will smoke upon startup only, and rings will make it smoke all of the time.

    <a target="_blank" href=http://www.community.webshots.com/user/wheelininco>www.community.webshots.com/user/wheelininco</a>

    " Wider IS Better!!!"
     
  3. Thunder

    Thunder 3/4 ton status

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    Do a compression test.
    Remove the plugs and check each cylinder with a compression guage. write down the PSI readings on each cylinder.
    Then squirt a teaspoon of oil in the cylinder and check the compression again.
    If the PSI reading increases, its the rings.
    If it stays pretty much the same it is the valves

    <font color=orange> You are just jealous, because the voices only talk to me.</font color=orange>
     
  4. denver75k5

    denver75k5 1/2 ton status

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    never thought of the squirting the oil thing, good idea!

    <a target="_blank" href=http://www.community.webshots.com/user/wheelininco>www.community.webshots.com/user/wheelininco</a>

    " Wider IS Better!!!"
     
  5. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Make sure it's a teaspoon of oil or you'll learn what hydro-lock is and the term, "bent connecting rod".

    I think it's valve seals. The first two letters in Chevy stand for "Cheap Heads" because they always smoke on startup. If your valve seals get really bad, it'll smoke on acceleration too.

    Tim
    '84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
     
  6. Adrock

    Adrock 1/2 ton status

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    ya. i have an 88 and it smoked all the time. so i thought it was the rings, and it kinda scared me cause thats real expensive. but i pulled off my valve covers and took a good look and found my valve seals were completely dead. so i put new vortec heads on and its all better now. hope that helps. or atleast makes you feel a little better.

    Adam
    a.k.a. Adrock
    88 Chevy Blazer FI 383
    "With great power there must also come great responsibility" -Spiderman
     
  7. RESTORE89

    RESTORE89 1/2 ton status

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    i am in almost the same shape, smoking at start and on hard accel, tell me about the vortec heads, are the better than than the regular stock, where how much will they monkey with the puter etc. I can pull the heads and take them to a local performance machine shop and they will magna flux machine due a valve job and all for about 150$
    chris


    It needs a bigger motor.
    what's in it now?
    doen't matter it NEEDS A BIGGER MOTOR
    89 350tbi/700r4h/np208/4.11's
     
  8. 84_Chevy_K10

    84_Chevy_K10 Banned

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    1. Yes they're much better than stock 40 horsepower minimum, add a cam and they're more
    2. They will not "mokey with the puter"

    The only downside to them is that they require a new intake(Edelbrlock Vortec TBI) and self alligning rocker arms. They're a far better design than your current GM heads. You'll like them.

    You can get them at your local GM dealer for $220 each.

    Tim
    '84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
     
  9. RESTORE89

    RESTORE89 1/2 ton status

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    are you making fun of me "monkey with the puter" LOL!!
    guess i will stick with the stock to much cash for now, and see if the shop can "tune" them some. going to change the cam and timing gear when i do the head work, and a buddy told me i could use a cam for a mercruiser marine engine, and they actually sell them at a performance shop locally for great low end torque. can i do this with the stock intake and tbi and not "monkey with the puter??


    It needs a bigger motor.
    what's in it now?
    doen't matter it NEEDS A BIGGER MOTOR
    89 350tbi/700r4h/np208/4.11's
     
  10. Adrock

    Adrock 1/2 ton status

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    there is a kit at scoggin dickey for a carb that costs like 670 bucks <a target="_blank" href=http://www.sdpc2000.com>www.sdpc2000.com</a> and if you need the special TBI manifold like i did it will cost you about 100 extra bucks depending on how you haggle. but it is great. i put in a new cam when i had everything apart and i got about 70 or 80 more HP. and better gas mileage. wasnt to hard. but you do have to have an idea what you're doin. but i would highly recomend them.

    Adam
    a.k.a. Adrock
    88 Chevy Blazer FI 383
    "With great power there must also come great responsibility" -Spiderman
     
  11. Neil

    Neil 1/2 ton status

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    Thanks for everyone's input. It smokes at idle too on the passenger's side only..I have true duals by the way. The driver's side smokes upon crankup and hard excelrtn, passenger side almost all the time. I have a weird truck man. I will check my heads first. What should I look for? I have never looked for this(bad valve guides) before, but I know what I'm looking at as far as it is supposed to look.Thanks folks!

    Neil H.. Alabama.. '78 K5 400ci 4x4 AT,AC,PW Cheyenne. '74 C10 3spd/floor 250ci 4x2
     

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