Kohler K series engine leaking tons of oil while running under load

[Alrashid2 355]

Hey guys. I've discussed a bit of this before on here but today was a real doozy. I bought my 312-8 with a K301 engine back a few months ago, and have just been using it to pull firewood around the property so far. Today was the first time i got to use it to plow the driveway. Took about 45 minutes but it worked beautifully, all without tire chains on a steep hill too!

 

Finished up and popped the hood to find just a ton of oil pushing out from every gasket on the front of the engine, and dripping down from the frame... such a bummer.

 

I have pulled the breather components apart before and I thought they all looked good, but I'm curious if specifically I can look for. Yes, it is put together correctly and in order... While running I put a piece of tissue paper over the breather cover hole. Hard to tell but air was pushing out... I think that is how it's supposed to work (push air out, not in, create a vaccuum...)

 

So much oil was pushing out that it was spewing up onto the exhaust muffler connection and burning...

 

No hour meter on this so who knows how much it has been used. I suppose it could be blow by from worn rings but the engine runs fine, no smoke at all in the exhaust fumes, and when I pop the oil dip stick I'm not getting a ton of oil pushing out. Air movement, yes, but nothing insane...

 

Any ideas here? I'm going to pull the breather again here shortly. Unfortunately rebuilding the engine is not in the cards for me, so if this is blowby I guess I'll just deal with engine oil leaking and topping her off... I'm wondering if there is some sort of "fix" that isn't technically correct but could help? Like what if I allowed the blowby to escape from the dip stick tube, so that it isn't pushing oil out every gasket instead? Any thoughts on that? Thanks guys...

 

Edit: uploaded a photo to show the amount leaking after just 45 min of running. No I have not done a leak test as I have read it's quite difficult on these engines due to some sort of bypass mechanism on the Kohler k series, and I do not have the equipment/expertise to do it...

 

Edited January 6 by Alrashid2

[oldlineman 1,487]

Are you sure your not overfilling the crank case?

[Alrashid2 355]

Oh ya. Just 2 quarts as per spec and dipstick says it was filled to the right level 

[OutdoorEnvy 1,678]

check if oil is on the sparkplug?  Verify breather inner plate was put on with the top up and the hole down. 

 

It's odd that you have oil by the muffler connection.  Are you able to wipe off and run it and watch to see where the leak is coming from?  If it's one area like the camshaft cover the gasket might be bad.  But if it's inside the head and exiting in or by the exhaust then either the valve train is pushing it up, like if it's not draining right.  Or the rings are so far gone oil is just pushing past the piston and rings easily. 

 

I have the same rig you do and the breather tube has a noticeable gust of air when turning the engine over.  You might remove the dipstick so the crankcase is open and try blowing through the breather tube to make sure it isn't blocked at all.

 

[Alrashid2 355]

Spark plug looked fine? Dark color but not wet... Just tore apart the breather components and everything was in order. Filter intact and clean, the reed component intact and perfectly flat and flexible... 

 

The exhaust oil looks to just be from near the governor area and I think it's just bouncing some drops up onto the exhaust is all. 

 

When you say breather tube, are you talking about the dip stick tube? I don't think I have a breather tube, just the breather component on the front of the engine under the carb.

 

I guess my real question is, if I'm not going to rebuild/replace the engine to properly fix the blowby, is there a work around? I know this wouldn't be correct, but I feel like I have two options at this point:

 

1. If the blowby is happening no matter what, can I allow the excess crankcase pressure to vent out the top of the dipstick tube, so it isn't pushing so much oil out the gaskets on the face of the engine? Or could I just open up the breather apparatus to allow more pressure to come out? 
2. I just keep driving it anyway. Blowby still happens but the pressure is escaping through the gaskets, pushing oil with it, instead of at the breather or the dip stick tube...

Edited January 6 by Alrashid2

[oliver2-44 10,019]

There are some Kohler breather covers that have a rubber tube coming out of them instead of just the stamped vent opening. 

Some just had a tube pointed down and some later models had a tube that vented to the carburetor.   (all modern engines vent the valve cover to the air cleaner box)

This is a Magnum 12 which has the same size cover as yours.  See hose #11

https://www.psep1.biz/arinet.asp#/Kohler_Engine/M12-471508_BASIC/Breather_%26_Vent_3-10-12_Created_4%2f%2f3%2f%2f2006/10959/CATALOGS|~35563

 

For a work around, you could tap the valve cover 'slit opening" closed.  Clean the metal very good and put a dap ove JB weld over the closed slit.

Buy hose #11 from above and drill hole in cover for hose to snap into.  (I've also seen these hoses with a build in 90 degree fitting to point it downward)

Extend the hose with some tubing from the hardware store to extend below the tractor  or into a collection container.

 

If you didn't want to modify your original vent cover, a new one would be a very simple part to make.

You could get a piece of flat steel  from the hardware store.  1/4" thick would be thick enough to tap for a pipe 90.

It could be a little wider if that's how standard metals sizes fit.

Drill the center hole for the rod, and a hole for the vent tube. tap for a 90 deg street ell.

Add a hose barb fitting and run hose as above.

 

 

[Alrashid2 355]

Thanks for weighing in @oliver2-44 that isnt a bad idea at all... I'll think on it. Could I not establish the same general idea though by installing something between the dip stick seal and dip stick tube? That way it's allow blowby to exit from above and keep the oil inside the crankcase...

 

I ran the engine at full throttle, sitting parked, for about as long as I was plowing, and just had some damp spots on the engine, but a few ounces of oil pooling everywhere like after I plowed. I assume it's safe to say that being under extreme load plowing like that caused more blowby? Is that how that works?

 

Would it be possible for me to just replace the piston rings only, not do a full engine rebuild, and stop this? What does fixing the blowby ring issue cost to have a shop do? I could stomach like $300 but not willing to throw $750+ into this unfortunately... Or would it be better advised to just find another K301 engine out there and swap engines?  Anybody here in SE PA do rebuild work on Kohlers?

 

Really shocks me that the rings are bad on this engine. I have no hour meter, but the thing is in such great shape. Minimal rust, body in good shape, was just used for mowing... such a bummer! 

Edited January 6 by Alrashid2

[Skwerl58 737]

Check the oil to make certain the fuel pump is not leaking fuel into the crank case. Smell it and also check it for thinning from fuel. My k series blew out oil after I got it going after it sat for a few years but most of the leaking stopped after a couple hours of work. Hope that you can get this resolved and get it running good.

[Alrashid2 355]

Thanks for the advice - I actually had a fuel pump leak when I got the tractor and have replaced. Oil level is not rising and doesn't smell like gas...

 

I'm debating allowing the blowby to vent out the dip stick tube. Curious what you guys think of that. 

[squonk 41,778]

When an engine does this it's usually something major. I said this in one of your first threads. Excessive blow by at the rings.  Top of piston eroded away or even could even be as bad as a broken piston.

 

 

[oliver2-44 10,019]

Yes you could install something at the dip stick tube.  But I suspect it might be hard to get a good seal. it it does seal around the dipstick tube, that's a new place for dirt to get into the engine.  

 

Any chance you have a machinist friend.  It sure would be nice to measure the cylinder top and bottom after you finished with snow and firewood season. 

That could help determine if there a possibility of reringing it vs a full overhaul.  

But if it has that much blowby I suspect the cylinder would be worn slightly egg shaped which means a rering wont help. 

 

 

 

[Alrashid2 355]

@squonk thanks for the photos. Yes hoping it isn't something too major - had I never popped the hood I would never even know the engine isn't pristine. Despite all the leaking of oil, I did check the dipstick after and I wouldn't have noticed that it went down...

 

@oliver2-44 good points. Maybe I could go along the route you were saying and make a second Breather cover and put on some sort of air filter component... On the flip side, the pressure is so strong that I doubt dirt would be making it into the engine! I'll do some thinking. 

 

I'm with you on the egg shape, simply because I know my luck and if I was adventurous enough to get in there, I could see that being the result!

 

I actually do have a machinist friend who I talked to a bit ago about this. He himself has some tractors, including a WH as well as some old Ford N series tractors from the 1950s. He said all his have blowby, with various levels of oil leaking out, and he won't fix them himself! "Too much work" and he said he just lives with it. Told me to "invest in paper towels and keep it topped off!" 

[oliver2-44 10,019]

1 minute ago, Alrashid2 said:

 

 

@oliver2-44 good points. Maybe I could go along the route you were saying and make a second Breather cover and put on some sort of air filter component... On the flip side, the pressure is so strong that I doubt dirt would be making it into the engine! I'll do some thinking. 

You wouldn't need any filter on the vent tube.  The slip you have in the cover now doesn't have a filter over it. 

The mesh inside the breather acts as a quasi oil mist catcher and as a quasi filter over the vent hole.  Just put the tube end into a plastic bottle with a small vent hole in the cap.    

 

I can agree with your machinist friend.  My C81  has a gray Service  Replacement Engine, so one would think it might have a chance of being in better shape, then again tractor was in a few pieces when  bought it for $50.  Anyway, I've gone through the vent checking, cylinder measuring, leak down test, etc. It's worn, but runs good and has plenty of power for my purposes.  It just gets parked over a diaper pad if its over concrete.  

 

Actually one think you could do just to confirm your obvious blowby is do a leak down test.  Your local auto supply or friend may have a leak down tester.  With it you can hear if the valve seats, valve guides, or piston is leaking and a % how much.  But then again, it doesn't fix the problem until your ready to rebuild it.

[Alrashid2 355]

Thanks @oliver2-44. Yes youre right, forgot about that little mesh filter... My only reasoning for not going the route is the fact that the breather/reed valve already seem overwhelmed by the blowby. I feel like if the breather wasnt overwhelmed, then all the oil would be coming out of the breather, but it's not - it seeps from all gaskets and the governor connections. I worry I'd go about modding the breather only for it to still not be able to keep up.

 

I was thinking of maybe removing the reed valve all together - I obviously have high pressure inside the engine so wasn't sure if that reed valve mattered. Maybe it'd allow the breather to open up more? 

 

I'm with you, was going to do a leak down test but I thought i read that the Kohler engines are difficult to test compression on due to some sort of over pressure valve or something? And like you said, it would just confirm the worn rings and wouldn't change anything... Does your C81 have blow? Oil leaking out too? I'm curious if this is more common on these old engines than the enthusiasts/perfectionists on here let on... thanks again

[Bar Nuthin 859]

17 minutes ago, Alrashid2 said:

I was thinking of maybe removing the reed valve all together - I obviously have high pressure inside the engine so wasn't sure if that reed valve mattered. Maybe it'd allow the breather to open up more? 

 

Someone with more knowledge than myself can chime in but, I believe the reed valve is intended to allow the crankcase to form a vacuum - not pressure. If your breather is clogged or assembled incorrectly, you may have pressure in your crankcase contributing the oil leaks you see. I'm not a mechanic, so I could be full of crap.

[oliver2-44 10,019]

55 minutes ago, Alrashid2 said:

I'm with you, was going to do a leak down test but I thought i read that the Kohler engines are difficult to test compression on due to some sort of over pressure valve or something? And like you said, it would just confirm the worn rings and wouldn't change anything... Does your C81 have blow? Oil leaking out too? I'm curious if this is more common on these old engines than the enthusiasts/perfectionists on here let on... thanks again

A Lead Down Test is different than a compression test. These old Kohler have ACR. Automatic Compression Release at slow cranking speed to make it easier on the starter. 
A Leak Down Test utilizes pressurized air input through the spark plug hole and uses air “flow” to determine leakage. You also listen at the muffler, dipstick tube, crankcase vent to “hear” where the leak is. 

[Alrashid2 355]

Thanks for explaining. I don't even have an air compressor so I don't think I'll be doing any leak tests...

 

Any chance this could caused by anything else? It's not the breather... Say it's not the piston rings either. Could it be a head gasket issue? Or could the valves be out of adjustment cause this?

[leabassett@sbcglobal.net 156]

How much oil did you need to add? A little oil goes a long way. If you only used a little I would not worry till spring. Just keep a eye on it.

[Alrashid2 355]

Didn't have to add any luckily. Oil level maybe moved down 1/16”... Just sprayed brake cleaner on the engine and wiped it away 

[oldlineman 1,487]

your 3rd post you stated you put 2 quarts of oil in this k301 I believe it only holds 1 quart of oil if I am correct and I think I am there is your problem, maybe you have the wrong dip stick in this engine. Garry what say you?

[Bar Nuthin 859]

11 minutes ago, oldlineman said:

your 3rd post you stated you put 2 quarts of oil in this k301 I believe it only holds 1 quart of oil if I am correct and I think I am there is your problem, maybe you have the wrong dip stick in this engine. Garry what say you?

 

My owners manual states 4 pints (= 2 qt)

 

[rmaynard 15,776]

K301S 2 quarts

K301AS 1 quart

 

I still think the reed valve is installed wrong.

 

 

Edited January 7 by rmaynard

[oldlineman 1,487]

my bad I guess I was thinking of the k301AS

[Alrashid2 355]

@rmaynard does the actual reed itself only have one direction?

 

My engine does say AS on it though I think someone said that it was probably reworked by Kohler prior to being thrown on a wheel horse.

[rmaynard 15,776]

Let's see a picture of the oil pan.

 

The reed needs to be in the correct location. Plate gasket goes against the block. Breather plate against the gasket with the recessed part facing the block. Then the reed, followed by the baffle, the filter, the rubber seal, the other gasket and finally the cover with the vent hole up, just like the diagram shows.

Edited January 7 by rmaynard