Overworked my eXmark,should I freak out?

Discussion in 'Mechanic and Repair' started by Russo, May 22, 2002.

  1. Bill c

    Bill c LawnSite Member
    Posts: 114

    Break in period is when the metal to metal surfaces wear into each other.One of the most critical areas is the piston ring to cylinder wall surface.With synthetics used for the break in it is possible for these surfaces not to wear correctly and cause excessive oil use.
  2. Russo

    Russo LawnSite Senior Member
    Posts: 287

    I guess I'll buy that. So your saying that a little wear is good to let the metal surfaces "fit" better. Appreciate your responses.
  3. khouse

    khouse LawnSite Bronze Member
    Posts: 1,465

    What Bill c said I believe is true. That doesn't mean that I'm right either. I will do some checking. I found that most automotive manufacturers say that you can use synthetic oil on the first oil change. I read years ago when we started using Amzoil that they recommended you to break your engines in with mineral oil. I found where some hi-po factory cars use syn right from the factory. Maybe these engines are broke in at the factory? I don't know. We all know that syn is slicker than regular oil. It just makes sense to me to greak your rings in then switch over. I'm going to call Valvoline and ask them also.

  4. Grasshog

    Grasshog LawnSite Senior Member
    Posts: 270

    Wonder why some new high end cars come all ready packed with syth oil.
  5. blairbuc

    blairbuc LawnSite Member
    from CT
    Posts: 154

    Just to add to the confusion of synthetic break in.

    My VW Diesel came new with synthetic. No break in.

    My 98 GM truck came with normal hydrocarbon oil. GM did not want synthetic in that engine until it was broken in at 25,000miles.

    My 1975 Onan diesel generator? Cummins/Onan said an engine that ran all those years on streight 30 weight non synthetic should not be switched to a synthetic. Wear patterns in the cross hatch of the cylinder walls were established and switching at this point would produce blow-by.

    Back in 1990 I talked to the Honda Tec that headed the team that wrote the manual on their V-6. He took apart engines and examined them literally under an electron microscope. That engine had chromed cylinder walls and he hated what synthetic oil did. Ok, that was 12 years ago and may-be things are different. He felt the synthetic was too slippery. This allowed the oil to go past the rings, into the combustion chamber were it left a residue in the combustion chamber. As this residue built on the chamber walls, the compression ratio increased making the engine octane thirsty and putting more load on the main bearings. Probably did not help the head gasket either.

    My brother was one who believes in synthetic from day one, no break in with cheaper oil. Not knowing that lifter noise was normal noise in his car he decided he needed new lifters at 83,000 miles one day. We pull them and found something amazing. No blueing to the metal, indicating heat. No wear on the milling marks left when a manufacturer spins the lifter body, or mills it round. These marks are always worn to flat and shinny with non synthetic oils. In short, those old lifters had no wear. They looked and mic-ed to the dementions of the new ones.

    Well, my brother always complained of lack of power. We drained out the synthetic after 83.000 miles and decided to break in a 8 year old car. Sounds a little strange, but after getting use to what a car will do being floored up the same hill everyday on your way to work, my brother said the car now had more power after going 15,000 miles on non synthetic. I think at this point he probably got the rings to seat for the first time. Should have been done the first year he had the car. Could be in his head, I'll never know, but one thing for sure, if you can't wear out milling marks off the side of a lifter, than what hope do you have of breaking in rings with a harder face.

    I now break in my engines on non- synthetic and then switch. I don't think 5000 miles is enough either.
  6. Plowguy99

    Plowguy99 LawnSite Member
    from MI
    Posts: 23

    Go by what the engine manufacturer recomends. If they recomend 30w then use it. If they recomend synthetic oil then use it. The engine companies do numerous tests when they design engines and they know what works best in their engines. Also, using synthetic oil will not increase your service intervals. Synthetic oils have a higher temperature at which they break down, but you still have to change your oil just as much. On my Exmark Lazer Z, the Kohler engine manual states that you can use synthetic oil, but it is not necissary. However, the hydraulic system states that only Mobil 1 5w40 can be used.

    ADLAWNCUTTERS LawnSite Member
    Posts: 191

    my kawi get what ever i have laying around and like it. my oldest is from 1987 and not one problem. i think it is more important to change it once in a while.
  8. Alan

    Alan Member
    Posts: 1,185

    I would appreciate an explanation of that line of thought. I'm running synthetic and using extended change intervals. 25 Kohler has run synthetic since the second change and I change once a season, about 250 hrs. Engine is dead clean inside and I can still read the writing on the dipstick through the oil on it after that interval. I put the rapid blackening of dino oil down to charring at the high temperatures these engines run. The synthetic ability to resist breakdown seems ot make the difference in that respect. Why NOT run extended service intervals? What are your facts to back up your opinion?
  9. Bill c

    Bill c LawnSite Member
    Posts: 114

    I run mobil 1 in everything and use extended service intervals with the exception of changing the filter midway and top it off .And like alan said the oil doesn't even get black.
  10. Alan

    Alan Member
    Posts: 1,185

    I forgot to mention that I DO change filters at the half way mark as well.

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