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black smoke from silencer!!!!

Discussion in 'Engine Compartment' started by jayakrishnakola, May 19, 2011.

  1. jayakrishnakola

    jayakrishnakola Regolare

    Messages:
    439
    Bangalore
    when i say black, i mean like old trucks.

    i noticed this first time when i was following a linea mjd on hiway before i purchased mine, but i then thought it was due to his lack of maintainance. i noticed it even in my linea during a trip i made with my friends to goa where i was driving my friends car following my linea. it starts exactly when the turbo starts kicking in. does any one else face this problem????:?::?:
    if it was a little less like what comes from a swift or a verna i wouldnt mind. but what im talking about is quite questionable.

    is there any cure for it, i mean its a bs4 complaint engine, it shouldnt smoke so much rite???
  2. gurjinder

    gurjinder Staff Member Janitor

    Messages:
    3,989
    Punjab
    If you floor the pedal before the turbo has spooled up, you are definitely gonna see black smoke ( More fuel + less air = black smoke ( imcompletely burnt fuel) ). And that is natural , not a problem.

    A blocked air filter would elevate the problem further.

    Give accelerator input smoothly and gradually, and you wont notice the smoke.

    Black smoke isnt worrisome. Blue is. :)
    harsh agarwal likes this.
  3. jayakrishnakola

    jayakrishnakola Regolare

    Messages:
    439
    Bangalore


    but actually i always thought turbo charger is a turbine( that runs when the exhaust gas is made to flow over the splines of the turbine- whose efficiency can be increased using an intercooler) coupled to an axial compressor with a single shaft and the compressor compresses more amount of air into the fixed volume of the cylinder for more of fuel to help burn and hence the excess fuel is also burnt providing more power during power stroke.
    if an engine is fitted with a turbo charger, the compressed air will help in the burning of excess fuel that is supplied into the cylinder and hence no unburnt fuel should be present after the power stroke.



    all this is from my text books and its only theory


    but practically we cant get 100% efficiency out of that power stroke because of mechanical loses and etc.....



    but anyway i feel that smoke coming out of the silencer is embarissing so im not flooring the pedal since the day i saw it come out from my linea,,,,,
  4. Dilip_dmk

    Dilip_dmk Superiore

    Messages:
    649
    Delhi, India
    New Delhi
    Grande Punto 1.2
    We can generally understand what is wrong with a diesel engine by the colour of smoke emitted from the exhaust.
    There are three basic colours - black, white and blue.

    Black Smoke

    This is due to a air to fuel ratio imbalance, either the fuel system is delivering too much fuel into the engine or there is not enough clean air (oxygen ) a few things to look for :
    •Faulty injectors (injectors need attention at about 100.000 to 120 000 miles)
    •Faulty injector pump
    •Dirty air cleaner
    •Turbocharger or intercooler faulty
    •Problems within cylinder head, valves clogged up due to faulty EGR (exhaust gas recycling unit)

    White Smoke

    Normally means that the fuel injected into the cylinder is not burning correctly. The smoke will burn your eyes.
    • Engine/pump timing out
    • Fuel starvation to the pump causing the pumps timing not to operate correctly
    • Low engine compression
    • Water/petrol in the fuel

    Blue Smoke

    The engine is burning engine oil
    •Worn cylinders or piston rings
    •Faulty valves or valve stem seals
    •Engine over full with engine oil
    •Faulty injector pump/lift pump allowing engine oil to be mixed with the diesel


    And a lot of other useful info about diesel engines given on - http://www.uniteddiesel.co.uk/diesel-engine-smoke.php
    Last edited: May 19, 2011
  5. gurjinder

    gurjinder Staff Member Janitor

    Messages:
    3,989
    Punjab
    @jaykrishn

    There's a difference between the turbo spinning and the turbo producing useable boost.

    At low rpm's , the exhaust gases are unable to spin the turbo at required speeds which can enable it to produce peak/usable boost. That is why , at low rpm's you experience " turbo lag". As the rpm's climb, the engine does more work, produces more exhaust which in turn spins the turbo up and hence you feel the boost.

    @dilip
    The info given by the website is absolutely correct.
    But jaykrishn's symptoms are merely of flooring the pedal while the turbo is still waking up.

    Cheers!
    Gurjinder.
  6. jayadev

    jayadev Esperto

    Messages:
    1,057
    Kannur, India
    Kannur
    Grande Punto 1.3 90 HP
    first thing.

    mjd is a diesal engine. no sudden high revving.

    it needs a specific time to adjust for best performance .

    huge cloud like black smoke from old truck is not possible from a normal mjd .

    fuel adultration or airfilter clogging can also lead to too much of black smoke .

    certain gas station mix additives to fuel like kerosene and such which can lead to black smoke.

    early morning if i floor the pedal i notice smoke in my punto90hp. but by midday or after some warming up it doesnt show much.
    Last edited: May 19, 2011
  7. gurjinder

    gurjinder Staff Member Janitor

    Messages:
    3,989
    Punjab
    OT-

    I hope you're flooring the pedal only when the engine is at its proper operating temperature and not cold.

    Gurjinder.
  8. jayadev

    jayadev Esperto

    Messages:
    1,057
    Kannur, India
    Kannur
    Grande Punto 1.3 90 HP
    ^^

    i mean, initial revs before warming up ,diesel engine acts jittery and if one floors pedal it does shows smoke(i dont mean blowing up turbo) .

    after couple of minutes revving it eases , then smoke is quite discernible which is quite normal imo.

    reasons could be anything from viscosity of engine oil to metallurgical nature of engine.
    harsh agarwal likes this.
  9. guys my drive early in the morning is 3 kms at the max from my home to college.
    i religiously follow the 90second idling rule. any thing might happen to the engine if i floor the throttle a few times to overtake other vehicles??

    the highway i travel is a 2 lane highway. 1 lanee for each direction.
  10. jayadev

    jayadev Esperto

    Messages:
    1,057
    Kannur, India
    Kannur
    Grande Punto 1.3 90 HP
    sri,
    90sec idling rule...........?
    rather drive immediately maintaining low rpms that is best for mjd engines.

    flooring pedal will not be a overkill because it is under safe tolerances . yet diesel engines are not for high revv driving but sedate and efficient driving.
    harsh agarwal likes this.

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