Help with a seized engine

Discussion in 'Shop Talk' started by Thoughthound, Jan 23, 2005.

  1. Thoughthound

    Thoughthound Well-Known Member

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    Yesterday I changed the oil in my lawn tractor and thought I put in enough replacement fluid, yet somehow my engine seized.

    Can't turn the flywheel by hand.

    So now what? Am I destined to tear it down, replace parts and bore the cylinder?

    Any advice would be appreciated and thanks in advance.
     
  2. fordy

    fordy Well-Known Member

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    ..............If , your engine is laying flat , might try removing the sparkplug and try pouring some Marvel Mystery oil in the combustion chamber(s) and give it a day or so to "soak" . Other than that you'll probably have to disassemble it to get the piston(s) out of the block . fordy.. :)
     

  3. Cosmic

    Cosmic Well-Known Member

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    Depends on how bad you siezed it. After putting in the Mystery Oil, or can use WD-40 or even some diesel fuel and letting it sit a few days, if it still won't budge can try using a little mechanical advantage on the drive shaft, (depending on if it uses pulley(s), belts or is direct connected. Whatever works, wrench, sockets, etc.

    Part of the problem is the aluminum where the bolts goes thru doesn't expand at the same rate as the rest of the cylinder and that is usually where the piston hangs up. So expect it to be siezed in a couple small areas.

    Usually you are looking at a tear down, maybe even scrapping in some cases, depending on parts sources, conditions, costs, etc.
     
  4. ranman

    ranman New Member

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    Your engine may not be ruined, if the piston is seized in the combustion chamber, but the extent of damage can only be determined by internal examination. Cylinder wall/piston damage is one thing, but crank damage can be more costly than the repair is worth, Was there a knocking/hammering sound before it seized? That would indicate rod and or crank damage. Overheat of the piston from lack of oil may be reversable. To unseize the engine, position the engine so that the spark plug is standing straight up and fill the combustion chamber with equal amounts of mystery oil, transmission fluid and brake fluid, if you have it. Mystery oil alone could do the job. After you have let soak for a day or more, use the mechanical advantage of the blade to work the crank back and forth, rocking it back & forth. If you get any movement at all, you should be encouraged. Keep at it until you get a complete revolution without binding. Naturaly as the piston comes up the fluid will pump out so be prepaired. Change the oil (fill it up this time, with the recomended oil) after draining the Mystery oil out. Put in a new/clean spark plug and listen for any knocking sound (the awful indicator of rod damage) when it starts. Be prepared for a shortened life span.
     
  5. Beeman

    Beeman Well-Known Member

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    Let's not get carried away and jump to conclusions.
    First, what type of engine is it? You say you changed the oil but you're not sure if you put enough in? How much did you put in? Now after changing the oil did you start and run it and it quit running? How long did you run it, if you ran it, before you say it seized? As someone else asked did it make noises when it ran?
     
  6. Thoughthound

    Thoughthound Well-Known Member

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    It's a Briggs 14 horse single piston, air cooled with overhead valves.

    There was no knocking.

    I honestly don't know how much oil I put back in. I made the mistake of reading the dipstick.

    The last time I changed the oil, I put in the recomended amount and that caused the engine to dump oil out the exhaust.

    So this time I was "careful."

    I ran it for about 100 yards and it slowly quit like it ran out of gas. I started it again, put it in gear and it died again.

    It occurred to me that maybe I didn't put in enough oil, so I checked the dipstick and it was dry so I put in about a quart over a 20 minute period, checking and filling and waiting.

    I turned the key again. It cranked once and froze.

    The battery is fresh and the starter wants to turn it.
     
  7. DrippingSprings

    DrippingSprings In Remembrance

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    on some small engines if oil happens to get on top of the piston through many differening possibilities it will seem locked up. Pull the spark plug and see if it will turn over. If you see oil coming out of the plug hole as you turn the engine over it may be overfilled with oil. i saw this alot when i worked at a atv/bike dealer years ago. all appearences would be lock up. we would remove the plug and kick the engine over a few times starter or pull rope etc and oil would go flying. drain the oil and add a little at a time and check the level again and it would run fine.
     
  8. Beeman

    Beeman Well-Known Member

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    As Dripping springs said, remove the spark plug and try rotating the engine. Any liquid on top of the piston will hydraulically lock the engine either gas or oil.
     
  9. agmantoo

    agmantoo agmantoo Supporter

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    You stated you added oil after the engine ceased to run and I would think you know for certain how much you added at that time. Drain all the oil from the engine and then subtract the amount you added after failure and inform us as to how much oil was actually in the engine when it ceased to run. I recently work on a Yamaha ATV that was locked and it was locked on gas as the needle and seat failed to close and the engine was full of gas.
     
  10. Thoughthound

    Thoughthound Well-Known Member

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    It must not have been too bad. I pulled the plug, and put in ATF and let soak for 24 hours.

    The starter broke it free and ATF came shooting out of the cumbustion chamber.

    I haven't tried starting it yet though.

    Thanks for all the assistance!