Changing the Oil

Discussion in 'Lawn Mowing' started by tiedeman, Jun 12, 2004.

  1. tiedeman

    tiedeman LawnSite Fanatic
    from earth
    Posts: 8,745

    Until today, I have always just drained the oil from the mowers, changed the oil filter, and then put some new oil in.

    Well, after reading the posts a few weeks ago about how some of you guys drain the oil, run new oil through it, and then drain it again it has made me curious to try it.

    I tried it today and I could not believe the gunk that was still coming out. I just left the plug open and dumped two quarts new quarts through it after draining the oil and the stuff that came out was unbelievable. I will definetly be doing this for now on.
     
  2. laborador

    laborador LawnSite Member
    Posts: 148

    Im curious to know if these guys are starting their engine and letting it run for about 5 minutes to loosend the oil up. If you changed the oil with a cold engine the oil is more clumpy. Just my thoughts
     
  3. tiedeman

    tiedeman LawnSite Fanatic
    from earth
    Posts: 8,745

    I always run the engine before changing to warm it up.
     
  4. beransfixitinc

    beransfixitinc LawnSite Senior Member
    Posts: 592

    I would suggest, that when changing oil if you notice a large portion of "gunk" when it is draining, to drain the oil, replace the plug, remove the wire from the spark plug (or remove the whole spark plug to release some of the compression) and then pour a degreaser formula (NOT WATER BASED) into the crankcase. If you have a rope start, give the rope a few good pulls to mix everything around and give the slinger time to slosh it around, key start, try to turn the engine over a few times. Remember, disconnect or remove the spark plug so that your engine will not turn over. Then drain the crankcase again. This should clean your insides out better than wasting fresh oil. We use Varsol in the shop.. but you may not have it available to you.
     
  5. Richard Martin

    Richard Martin LawnSite Fanatic
    Posts: 14,700

    Although I have never done the "waste 2 quarts of oil" trick I have had opportunities to open up a couple my engines to replace seals, lifters, adjust valves, replace head gaskets etc. I have never seen anything inside my engines except for the parts that are supposed to be there and oil. If you do the oil and filter changes and air filter servicing at the recommended intervals you should not need to flush an engine.
     
  6. Green Pastures

    Green Pastures LawnSite Silver Member
    Posts: 2,457

    Amen.........
     
  7. DennisF

    DennisF LawnSite Bronze Member
    from Florida
    Posts: 1,381


    Ditto!!! If you are getting "Gunk" coming from the crankcase of your engine, you are not changing the oil often enough or you are not keeping the air filter clean or both. That gunk that you see coming from the crankcase is dirt that got into the oil. The easiest path for dirt to enter the engine is through the air filter. The single most important step in keeping the engine oil clean is to keep the air filter clean, clean and clean!
     
  8. gl1200a

    gl1200a LawnSite Senior Member
    Posts: 518

    In order for all of the gases, contaminants and acids to be drained with the old oil, the oil must be warmed to full operating temperature so all of the 'bad stuff' is fully suspended in the oil to be drained out. The most harmful contaminant in old oil that does the most harm to engines are acids that are collected in the oil during operation. There should be absolutely nothing else left in the engine to be cleaned out with further use of any more oil or fluid being added and drained past the initial oil drain and filter removal.

    I am fairly new to these forums and all, but have many years of experience with engines, lubricants and filtering. Including hundreds of oil analysis with metalurgy on high performance motorcycles, cars and jet helicopter engines.

    In my opinion... if you are able to get any type of comtamination out of the engine, after the initial oil drainage, you have other issues. Everyone can also be helped by using synthetic oils, period. There is way too much proof for any other conclusion.
     
  9. ZX12R

    ZX12R LawnSite Senior Member
    Posts: 787

    "Although I have never done the "waste 2 quarts of oil" trick I have had opportunities to open up a couple my engines to replace seals, lifters, adjust valves, replace head gaskets etc. I have never seen anything inside my engines except for the parts that are supposed to be there and oil. If you do the oil and filter changes and air filter servicing at the recommended intervals you should not need to flush an engine. "

    Agreed,I have motors 10 and 15 years old still running fine today although I did rebuild the 15 year old motor which is an 18 HP Magnum. The only bad thing about it,is that it drinks gas like a pig compared to the newer motors.
     
  10. 65hoss

    65hoss LawnSite Fanatic
    Posts: 6,360

    Gunk means you are not maintaining the equipment correctly.

    At the end of the day when its time to change the oil I bring the mower into the shop and let the oil drain all night. In the morning put the new filter on and 2 qts of oil and off to the races again.
     

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