Kohler 20hp command

[John2189 542]

Oil inside air filter. Blowby out of dipstick. Im guessing either bad  pvc valve or blown head gasket. How do I tell what it is? Does not smoke or use oil. If head gasket, how do I tell which cylinder?

horizontal shaft  

Edited May 29, 2022 by John2189

[Jeff-C175 7,206]

Often these are symptoms of a plugged crankcase breather but I'm not familiar with that engine.  Make sure there's not too much oil in the engine.  Head gasket would be pretty low on my list.  Compression, or better yet a cylinder leakdown test would be a way to test head gasket.

[John2189 542]

If the breather is plugged, how and where is the oil coming from?

[Jeff-C175 7,206]

3 hours ago, John2189 said:

If the breather is plugged, how and where is the oil coming from?

 

Good question... not sure... The breather has a reed valve in it and they can get stuck.  First thing I would check and if valves are adjustable, do that while I was in there.

 

But you've got crankcase pressure building up and a head gasket won't do that.

 

You mentioned PCV valve, not sure that engine has one.  I think that's more or less the function of the breather.

[John2189 542]

Ok I’ll check the breather

 

i thought there was an oil passage in the head gasket that sometimes blows. 

[Jeff-C175 7,206]

8 minutes ago, John2189 said:

thought there was an oil passage in the head gasket that sometimes blows. 

 

Hmmmm...  maybe  you're right !  I'm thinking flathead engines.  The Commands are OHV aren't they?  So yes, perhaps there is an oil passage there and if the gasket is blown just right it could pressurize the crank.

 

Like I said, I'm not familiar with your engine, but nobody else seems to be helping you !  

 

 

[John2189 542]

Yes its ohv. I’ll check the breather. If thats ok I’ll pull the heads. 
 

what it is doing is it is getting oil on the air filter and causing it to flood out. Not getting enough air. 

[Jeff-C175 7,206]

22 minutes ago, John2189 said:

Yes its ohv. I’ll check the breather. If thats ok I’ll pull the heads. 
 

what it is doing is it is getting oil on the air filter and causing it to flood out. Not getting enough air. 

 

If you've got an air compressor and can rig up a way to put air into the spark plug hole...  (I broke the center out of an old plug and brazed an air fitting in)

 

Put the cylinder to TDC, put about 50 PSI in, and listen at the intake, exhaust, and oil fill for air noises.  You'll hear 'some' at the oil fill due to normal air leaking past the ring gaps, but if it's 'extreme', you'll know something without having to tear down the engine first.

 

You could get fancy and add a couple valves to make a 'leak down' tester.

 

 

[John2189 542]

Well I was going to remove the valve covers and turn it over to see if it was leaking 

[John2189 542]

On 5/31/2022 at 3:26 PM, John2189 said:

Well I was going to remove the valve covers and turn it over to see if it was leaking 

Ok I pulled the valve covers and saw nothing. The valves are hydraulic so no adjustment there. Both spark plugs are the same color. I guess the next step is to pull the heads. 

[Jeff-C175 7,206]

12 hours ago, John2189 said:

next step is to pull the heads

 

You don't want to, or can't, do a leakdown test?

 

[John2189 542]

2 hours ago, Jeff-C175 said:

 

You don't want to, or can't, do a leakdown test?

 

Yes I can i wonder if Oreillys rents a kit

[Jeff-C175 7,206]

5 hours ago, John2189 said:

Yes I can i wonder if Oreillys rents a kit

 

They might... and it would tell you right off the bat if you have to do one, or both, gaskets... although, if I only HAD to do one, I would probably do both anyway.

 

 

[John2189 542]

Yes I would do both 

[John2189 542]

I put air to the cylinders. Left one ok but right one has bubbles from the hole that the push rod goes through.  Mabey the grass will slow down growing in a couple weeks so I can change head gaskets

[doc724 925]

I had one of these in my 5xi and did not experience any of the symptoms you state.  That being said, I I had a 416H with the Onan engine and I had oil spitting out of the air filter.  I am very meticulous when caring for my machines but I must have had a brain fart when I changed the oil.  With the machine on level ground, I pulled the dipstick and it was over filled but not by much.  I cleaned up the air filter, cracked open the crankcase drain and drained out a 6 inch diameter "puddle" into a drip pan.   Problem solved.

 

In my experience, I always try the simplest cure first.  8 out of 10 times, it works.  For the 2 out of 10 times it does not work, I find someone else who has more experience than me.

[John2189 542]

12 minutes ago, doc724 said:

I had one of these in my 5xi and did not experience any of the symptoms you state.  That being said, I I had a 416H with the Onan engine and I had oil spitting out of the air filter.  I am very meticulous when caring for my machines but I must have had a brain fart when I changed the oil.  With the machine on level ground, I pulled the dipstick and it was over filled but not by much.  I cleaned up the air filter, cracked open the crankcase drain and drained out a 6 inch diameter "puddle" into a drip pan.   Problem solved.

 

In my experience, I always try the simplest cure first.  8 out of 10 times, it works.  For the 2 out of 10 times it does not work, I find someone else who has more experience than me.

Thanks the oil level is a tad shy of being full.  It’s definitely a bad head gasket.