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jlslavey
07-20-2007, 09:56 PM
I have a 18hp Kohler command, recently I've been getting a lot of oil into my air filter. I took off the breather and cranked the engine over, oil shot up through the rubber tube that goes into the bottom of the breather assembly. Can anyone tell me whats going on? I've seen mist come through the tube but this was a steady stream of oil. Help!!!

newz7151
07-20-2007, 11:59 PM
Did you...... overfill it?
If not, replace the breather assy.

DOLMARatOS
07-21-2007, 12:42 AM
If it isn't a breather assembly it could very well be a blown head gasket. Not enough to notice a loss in power but sufficient to pressurize the crankcase and force the oil out.

Only true way to diagnose is to pull the cylinder head. sorry.

newz7151
07-21-2007, 08:08 AM
Only true way to diagnose is to pull the cylinder head. sorry.

Or hook up the leakdown kit and see what blows.

DOLMARatOS
07-21-2007, 10:03 AM
Or hook up the leakdown kit and see what blows.

You may get leakdown out the oil tube and breather. At that point, pull the valve-covers, drain the engine oil and spray some light oil down the cylinders and watch down the pushrod tunnel for bubbles.

jlslavey
07-21-2007, 01:33 PM
If it isn't a breather assembly it could very well be a blown head gasket. Not enough to notice a loss in power but sufficient to pressurize the crankcase and force the oil out.

Only true way to diagnose is to pull the cylinder head. sorry.

I did a compression check and one was 163 the other 175. I'm not too familiar with this part of the engine . I took off the breather cover and inspected everything. The reed was ok, and I could not see anything else that could be broken. Am I correct in thinking that when the oil comes into the channel for the oil sended unit then it overflows in the reservoir where the filter is, then proceeds to drain out the hole in bottom of the reservoir? About how fast should the oil leave through this hole if the engine is not running?

thecrankshaft
07-23-2007, 01:16 PM
Vertical or horizontal?

jlslavey
07-23-2007, 04:20 PM
Vertical or horizontal?

its a horizontal crank, I included other info in another topic that may or may not help, thanks for the reply

thecrankshaft
07-23-2007, 05:54 PM
Horizontal - that means the reed valve and breather filter are located underneath the breather cover below the carburetor. I would do a crankcase vacuum test; you may have pressure in the crankcase.

jlslavey
07-23-2007, 06:04 PM
Horizontal - that means the reed valve and breather filter are located underneath the breather cover below the carburetor. I would do a crankcase vacuum test; you may have pressure in the crankcase.

Here's what I've done so far, checked reed valve and new gasket installed, I just went out and tried a leaktest, I took off the pressure on all the valves(by loosing up rocker arms) tried it with them tight but kept turning engine over, so with all pressure off valves, I blew about 60-80 lbs air into plug hole, (sealed with a compression test fitting so as too have no leaks) I felt air coming through the carb, not a lot but enough to feel it, and felt like it might have been coming around the valve area. any ideas what might be going on ( such as valves not sealing ) just a wild guess. I've rebuilt car engines but this baby is a little different> thanks for any info you can give me.

barnard
07-23-2007, 10:22 PM
I'd say head gasket leaking . compression leaking into crankcase at the push rod cavity blow ing oil out breather.I always suspect the head gasket on OHV engines that blow oil.