Kohler CH-25S Crankcase Pressure Build-up

Discussion in 'Mechanic and Repair' started by mowermankevin, Mar 16, 2013.

  1. mowermankevin

    mowermankevin LawnSite Senior Member
    Messages: 270

    *trucewhiteflag*Just took an engine down for valve-job,lifters, head gaskets,crankcase breather reed & gasket, put it back together and runs great except it's blowing oil from the crankcase breather hose into the air filter housing. The owner said it started doing this last summer & and it will flood the air filter with oil after an hour of run time. Pulled it back down to check for blocked oil passages, cylinder leak down, the usual culprits, any ideas ? This is a 3100 hour engine & Spec#PS68521. I told him back in 1996 if he got a couple years out of it.... Thanks all in advance
  2. piston slapper

    piston slapper LawnSite Platinum Member
    Messages: 4,337

    If the reed valve was installed properly...
    You have a ton of blowby on the piston rings..
    A fresh set of heads would make weak rings blowby even worse..
    Do a leakdown test...
  3. mowermankevin

    mowermankevin LawnSite Senior Member
    Messages: 270

    P Slapper, thanks for the reply, we did leakdown last night & #1 cyl. intake valve is leaking, never had a bad valve job outta this machine shop for years until now. Put the engine in the truck to take back to the shop this A.M. to see what they have to say. Any more possibilities out there? Thanks Y'all
  4. Landrus2

    Landrus2 LawnSite Fanatic
    Messages: 5,050

    Hey Kevin If your reed assembly is good.I agree You will need to replace your rings. A valve not sealing will not affect the blow by.

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