kohler giving me hell

Discussion in 'Mechanic and Repair' started by 97firebird, Jul 1, 2005.

  1. 97firebird

    97firebird LawnSite Member
    Messages: 41

    Oh, here is my problem..still....My 1992/3 Kohler Magnum 20hp motor has been blowing oil out of the PCV valve like crazy and leaking out of the valve cover gaskets...This past spring we rebuilt the following....pistons, rings, honed cylinders, valve job, valve clearance, etc. all new gaskets, new breather plate, breather gasket, and checked the oil pressure regulator. I am sure that I have the correct oil level and viscosity in the motor. All of this still did not solve the problem, although the motor runs beautifully now. Could it be valve seals (There are only valve seals on the intake valves, which I replaced, but have not run the motor with them in yet)? Valve guides? Have yet to check them but I have the specs...It seems as though the crankcase is becomming too highly pressurized and/or filling the valve area up and forcing oil out of the PCV. I have had it with this motor so any help would be greatly appreciated. Thank You
  2. freddyc

    freddyc LawnSite Senior Member
    Messages: 578

    I have a 20hp Kohler Command that is pushing oil out the breather tube. Haven't had time to do any pressure checks yet, motor runs fine, but the air filter plugs with oil over time. I have nothing coming from the valve covers or anywhere else though. If you have access to a pressure gage (manometer) then checking for a pressurized crankcase might not be a bad idea. If not, does the oil flow increase out the breather when the engine is at higher rpms?? Someone suggested that there was a replacement breather for some models..don't know if its true. I saw that if your engine only blows by at igher rpms then its possible that the breather area is too small to vacate the pressure fast enough. Again don't know if its true.

    If you've already replaced rings and so on, its almost got to be a breather issue. Are you sure you don't have a port blocked or something? I saw that someone said that Kohler has ports in the cylinder walls and that this also can be a blockage point. If you've had it apart, I'm sure you know a lot more than me about the construction though. When you tore down the motor, did you soak the bloak in any type of cleaner??

    Please let me know what you find..my engine is about the same year and I don't want to rip it apart if I don't have to!
    Good luck.
  3. 97firebird

    97firebird LawnSite Member
    Messages: 41

    The motor runs perfectly fine with no oil dripping. It only starts to drip out of the valve covers when the motor is under load for a little while. I can't see what could plug the breather system really...Its is only an umbrella valve and a hose. However, I have been hearing a lot about a breather problem..but I think the replacement you are referring to is for the newer model Kohlers. Thanks for the input though.
  4. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    If you refer back to the service bulletin I posted in one of your other threads about the installation of the breather assembly they gave the part number for a new reed style breather assembly to take the place of the old umbrella type
    because there was a problem with them.
    BTW; Did you get the cylinder leak-down test performed ?
  5. 97firebird

    97firebird LawnSite Member
    Messages: 41

    I actually do have a new style with a reed...and the one i replaced mine with was new. I actually have not had the leak down test performed and the motor is apart again now so I can't do it yet.

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