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Kohler CH18s leaking oil from front and rear oil seals

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tomscub_2018
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2019/03/17 15:49:31 (permalink)
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Kohler CH18s leaking oil from front and rear oil seals

Hello,
New member here. This might be a long post so bear with me. I was given a 1995 Cub Cadet 2185 lawn tractor with a Kohler CH18s spec 62509 624 cc v-twin. I had to buy a used head to put on one of the cylinders as it was missing the head. When I took the engine off and took the shroud off, the inside of it was caked with dirt and oil. Cleaned up and put everything back together. Run good for a while then I started to notice oil on the back of the muffler box. Found oil leaking out of that seal. Checked seal under the flywheel and saw that it was leaking also. While I have the engine apart should I check or replace anything else? Why would the intake port have black carbon inside it on the cylinder that I did not replace the head or head gasket? I have not done a leak down or compression test as yet. Don't want to have to take pistons and stuff out if I don't have to. Any help I can get would be greatly appreciated.
 
Plan to blow snow with it next winter if everything is OK with it.
 
Thank You
Tom S.
Wells, MN
 
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    AVB
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    Re: Kohler CH18s leaking oil from front and rear oil seals 2019/03/18 08:42:56 (permalink)
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    Does sound like excessive blow by. Check the crankcase vent (PCV) for plugging.
     
    Also do a leak-down test. Disable the valve train test at TDC and BDC, Reason for the BDC is that there may be cylinder tapering and ovaling that does show up at TDC. This procedure is not mention the tester instructions but I discovered it by accident on a Tecumseh that had excellent leak down results but still smoked. On that engine I had 10% at TDC but had 60% BDC. I verified during tear down that the cylinder was indeed tapered.
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    tomscub_2018
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    Re: Kohler CH18s leaking oil from front and rear oil seals 2019/03/19 21:31:04 (permalink)
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    One of the head gaskets is leaking I believe. Found it covered in oil. Am I on the right path?
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    Roy
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    Re: Kohler CH18s leaking oil from front and rear oil seals 2019/03/20 00:16:29 (permalink)
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    That will definitely cause the problem, there is supposed to be a slight vacuum in the crank case.
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    AVB
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    Re: Kohler CH18s leaking oil from front and rear oil seals 2019/03/20 08:48:21 (permalink)
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    Before just replacing the head gasket verify that head is not warped out of spec which is no more .003" of flatness.
     
    I also recommend you download the http://resources.kohler.com/power/kohler/enginesUS/pdf/24_690_06_EN.pdf Service manual from Kohler.
     
    This will give you all the torque specs. But I would use a three step torque sequence for the cylinder head instead of the two step that is in the manual; just makes it less likely to warp a head during install [10-20-30.8]. Also per instructions as which sequence to tighten the bolts (screws).
     
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    tomscub_2018
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    Re: Kohler CH18s leaking oil from front and rear oil seals 2019/03/23 21:30:49 (permalink)
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    Changed front and rear oil seals and still have a big oil leak lost a quart of oil in about 15 minutes. If I face the engine looking at the cover plate the left side has oil all over the engine the right part of the front is dry no oil. Found oil inside of the exhaust port on #1 cylinder head so I am assuming that the head gasket is either leaking or blown causing the air from the fan shroud to blow the leaking oil all over the closure plate of the engine.
    post edited by tomscub_2018 - 2019/03/24 14:40:51
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    AVB
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    Re: Kohler CH18s leaking oil from front and rear oil seals 2019/03/24 20:27:14 (permalink)
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    Then it might take using UV dye to find the source of leak. Manometer will tell if the crankcase is pressuring to much which is probably blow by or it could a simple blown gasket that you have overlooked.
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    tomscub_2018
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    Re: Kohler CH18s leaking oil from front and rear oil seals 2019/03/24 20:39:50 (permalink)
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    Thank you for the reply. Yes the head gasket did look a little beat up and found a couple of spots on it where oil could leak. Which way should the dip stick tube go in? From outside the cover plate in or from the inside of the cover plate out? I think someone might have put it in the wrong direction causing oil to leak from it.
     Your thoughts on this would be appreciated.
     
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    tomscub_2018
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    Re: Kohler CH18s leaking oil from front and rear oil seals 2019/03/30 14:31:17 (permalink)
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    Found the oil leak underneath the breather. The gasket showed signs of leakage and you could see it. RTV'd gasket with ultra black. Waiting to see what happens.
     
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