Good Idea Bad Idea? drive a civic with no compression on a cylinder

Discussion in 'Civic' started by T L via, Nov 29, 2005.

  1. As mentioned in previous posts, my sister's 99 civic has a damaged valve on
    cylinder 3 due to a timing belt breaking. The car is running, albeit poorly
    due to no compression on cylinder 3. Once you rev it up, it sounds OK.

    Would it be safe to drive the car across town to a different mechanic in this
    condition? What are the risks? Or should it be towed?

    The drive would be in the city, 50 km/h or less, and revved as low as
    possible. Its about a 14km trip.

    Please advise.

    Terry in Winnipeg
    T L via, Nov 29, 2005
  2. and by risks, i mean could we do further damage to the
    cylinder/piston/valvetrain by driving with no compression and a damaged valve.

    T L via, Nov 29, 2005
  3. -------------------------

    I'd remove the spark plug wire from the plug and put an old 'dummy' plug
    on the wire, with the metal part of the plug grounded, so it sparks
    normally. Otherwise, I doubt anything bad could happen. (the high
    tension needs to find it's way to ground or it will 'blaze a new trail"
    inside the cap, or igniter)

    'Curly Q. Links', Nov 29, 2005
  4. Curly, not sure what you mean. How could I ground the 'dummy' plug? (IE
    make it stay grounded while driving the car.)

    Also, if the gas in the cylinder is not being burned off, wouldn't it cause
    the oil on the cylinder wall to be washed away, causing potential damage to
    the rings, and contamination of the engine oil? This is one of the big
    concerns I have.

    T L via, Nov 29, 2005
  5. This brings me to what I would add - disconnect the injector. Injecting fuel
    into that cylinder will come to no good.

    Michael Pardee, Nov 29, 2005
  6. T L via

    Jim Yanik Guest

    yes,the unburned fuel will throw off the O2 sensor,and the ECU will
    misadjust the other cylinders.

    Better to just leave the spark plug the way it is,not provide a "dummy"
    Jim Yanik, Nov 29, 2005
  7. Thanks for everyones input! I will unplug the injector and leave everything
    else as is. For a short trip, I doubt it will create any big problems.


    T L via, Nov 30, 2005
  8. T L via

    MAT Guest

    I'm imagining the combustion chamber pooling up with unburned gas, or would
    it just shoot out the exhaust valves anyway?
    MAT, Nov 30, 2005
  9. T L via

    G-Man Guest

    Is it really worth it to try? What will you save? $50 or less?

    I wouldn't do it.

    G-Man, Nov 30, 2005
  10. --------------------------

    The other guys are more correct . . Unplug the injector. No worries
    about any backfiring, but you might still generate a 'misfire' code, but
    so what? At least it can't backfire if there's no fuel/air mixture

    I was referring to chassis ground, like any part that's steel. Doesn't
    matter anyway, but it's worth remembering. Honda spark has to go
    _somewhere_ or it will go to the wrong places.

    'Curly Q. Links', Nov 30, 2005
  11. T L via

    jim beam Guest

    14k's are no problem. it's just one or two valves a little open -
    nothing different to a burnt valve. and don't worry about driving
    normal speed - if anything it'll be better as you'll get less blowback
    if it's on the intake side.
    jim beam, Nov 30, 2005
  12. T L via

    Eric Guest

    With one of these, part number 2756 for HEI

    Eric, Nov 30, 2005
  13. T L via

    Jim Yanik Guest

    Of course it would get pushed out the exhaust.The cylinder still remains an
    air pump.A little leakage around a bent valve is not going to stop that.

    The injectors atomize the liquid,so it will be a burnable fuel-air
    mix,vapor,not a liquid.
    Jim Yanik, Nov 30, 2005
  14. T L via

    Jim Yanik Guest

    Let it spark in the cylinder,it won't harm anything.
    No fuel-air mix to burn with an injector disabled,but that does not matter.
    Those engines(non-Honda) that share a coil between two cylinders do the
    same thing;allowing a spark in a cylinder with no fuel-air mix.
    Jim Yanik, Nov 30, 2005
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