Low Oil

Discussion in 'Mechanic and Repair' started by msb1766, Mar 20, 2007.

  1. msb1766

    msb1766 LawnSite Member
    Posts: 19

    I have a Craftsman GT 5000 series tractor with a Kohler Pro 25 hp motor (model #CV730S) , It seams to be eating oil, There are no leaks or puddles when it sits and not running but when I run it for about and hour and check the oil the dip stick shows about half way between "add and full". I always check the oil before I start it up and have to add oil if I run it more that a half an hour. I have 104 hours on the motor and bought this tractor new about 3 years ago. The problem started about 2 months ago. I have never had to add oil before was always on full.
    Is there anything that I can check before I take it to my local dealer? I know it has over head valves could the problem be there?
     
  2. thecrankshaft

    thecrankshaft LawnSite Member
    Posts: 172

    The head gasket is probably blown. Remove the spark plugs and see if one is darker and has more carbon on it than the other. If so, the head gasket on that side is blown. Your engine is out of warranty, but there may be something Kohler can do to help you. I find it unlikely that Sears will do anything about it.
     
  3. msb1766

    msb1766 LawnSite Member
    Posts: 19

    I will check the plugs, I didn't even bother calling Sears I call a local Kohler engine dealer and they said to bring it up anytime, If it is a head gasket is this something I could do or leave it to them?
    What is involved In changing a head gasket?
    I am assuming there are two heads being a twin cylinder correct?
    So change both or just the one that looks bad?
     
  4. thecrankshaft

    thecrankshaft LawnSite Member
    Posts: 172

    There are two heads and two head gaskets. I would just change the one that is bad. It's not that hard of a job, but I don't know your background. You can leave the engine in place, remove the blower housing, valve cover, screws for the baffles and bend them back, remove the intake manifold on the one side, unbolt the muffler, remove the bolts for the speed control bracket, then the four bolts that hold the head on. Make sure the head isn't warped and then make sure the mating surface is clean. Use a torque wrench for putting the heads back on. Kohler's service manuals are online at www.kohlerengines.com
     
  5. pugs

    pugs LawnSite Gold Member
    Posts: 3,022

    Could be a problem with one of the breather valves not sealing properly.
     
  6. thecrankshaft

    thecrankshaft LawnSite Member
    Posts: 172

    True, but if one plug has more oil carbon than the other, usually a head gasket. There are two breather reeds, only accessible by removing each cylinder head.
     
  7. J&R Landscaping

    J&R Landscaping LawnSite Fanatic
    Posts: 5,096

    The 25 hp kohlr v twins did have a head gasket problem. They have kits that have everything you'll need. I would leave it to the mechanics to fix though.
     
  8. VegetiveSteam

    VegetiveSteam LawnSite Senior Member
    Posts: 297

    How much oil is it using?
     
  9. msb1766

    msb1766 LawnSite Member
    Posts: 19

    About a 1/2 quart in about and hours of use.
     
  10. VegetiveSteam

    VegetiveSteam LawnSite Senior Member
    Posts: 297

    With it using that much oil in that short of time I would be thinking head gasket. The gasket gets a small breach between the combustion chamber and the push rod area. Normal tests like a cylinder leak down and a compression test many times won't show that as being the problem. It's still a good idea to do those tests before you have the engine torn into. What happens is the gasket is able to be pulled in a bit on the intake and power stroke of the piston and when you have pressure in the cylinder with either a compression test or a leak down test the gasket can seal and not show a problem. Unless the engine has eaten a lot of dirt I would bet on the head gasket. Pull the plugs out of it and see if one appears more oil fouled than the other. The one that is oil fouled will of course be the cylinder with the suspect head gasket. The CH25 is known for some head gasket issues but overall the percentage of engines affected is quite low. The problem has been corrected with a new head gasket and I wouldn't be afraid to put any Kohler engine up against any other brand of engine out there. Parts are more readily available than some of the other brands and Kohler has been known to be quite liberal with their warranty policy.
     

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