M20 burning a little oil

[TunaSlayet 88]

I am looking for opinions on my options here. I have a 420 LSE that has been cannobalized at some point in its life, and it now is used as a worker ( might be getting a kwik way fel) It uses about 1/4 of a quart of oil over the 25 hour oil change interval, not too bad. I am definitely interested in pulling the heads and having a look, but after reading the service manual,
rings did not look too much harder. So my options are:
-Do nothing
-pull heads/clean/adjust valves
-replace rings/pull heads/clean/adjust
-full rebuild from local engine shop-(lots of cake-probably not gonna happen)
 

[Fordiesel69 233]

Do you see smoke from the EX when you jab the throttle or when you enguage the deck?  If not, leave it alone.  If it is starting to smoke, then its time.

[TunaSlayet 88]

It smokes on start up a little, but no noticeable smoke while running. So the regular oil checks and top off is fine for a while longer? Here is a quick video of it idling and running after being worked for an hour or so. 

https://m.youtube.com/watch?v=8a6mIeVgaI0

[Fordiesel69 233]

Yes, you are fine.  Smoke on start is oil that leaks thru the valve stems, in addition to some possible oil leakage thru the rings while sitting.  Horizontal piston placment engines are noted to leak just a bit.  Brand new radial aircraft engines leak oil into the lower cylinder. 

Also you will need to run only these two weights of oil during the summer:
SAE 30 (Preferably a diesel oil like shell T1)

SAE 5w-40 (Full synthetic Diesel Oil)

SAE 15w-40 (Regualar diesel oil)

If using car oil or multigrades, it WILL burn oil.  Diesel oils do have special additives to keep flat tappet cams safe. 

 

[PaulC 341]

Yes, you are fine.  Smoke on start is oil that leaks thru the valve stems, in addition to some possible oil leakage thru the rings while sitting.  Horizontal piston placment engines are noted to leak just a bit.  Brand new radial aircraft engines leak oil into the lower cylinder. 

Also you will need to run only these two weights of oil during the summer:
SAE 30 (Preferably a diesel oil like shell T1)

SAE 5w-40 (Full synthetic Diesel Oil)

SAE 15w-40 (Regualar diesel oil)

If using car oil or multigrades, it WILL burn oil.  Diesel oils do have special additives to keep flat tappet cams safe. 

 

​That's an interesting read never heard of diesel specific oil before  Is this something you run in all of your tractor engines or just ones that shows signs of being tired? Are there any downfalls to running the diesel grade oil? I run just regular sae 30 in the kohlers I have all year round.

[Fordiesel69 233]

The subject of oil is super deep. 

To summerize, API Service SA thru SN (which is what we are currently on) is used in gasoline engines.

API Service CA thu CJ-4 is used in Commercial engine (Diesel)

Using gasoline oils in diesel is very harmful to the engine.  However using diesel oils in a gasoline engine is almost always a huge benfit as long as there is no emmission system installed.  Diesel oils are formulated much better as the engines have more somplex systems that cause shearing of oil, extreme acid production, soot, and in some cases more blowby gasses that need dealt with.  Our kohlers weak point is the flat tappet to cam surfaces.  Being you can rebuild a kohler about 3 times, you really need the cam to last that long.  That is about 6000 to 7500 hours.  The tallest part of the cam;s eccentric lobe will begin to wear and get to point that performance decreases.  Diesel oils are your friend in small engines.  A little zince additive will not hurt either.  Just avoid the all in one miracle in a bottle additives.

Tons of reading avail at:  www.bobistheoilguy.com

[PaulC 341]

Thanks for the info Forddiesel and ill check that link out. Do you have a link to the exact oil you run? Something im going to look more into and maybe change over on my next oil changes. 

[Fordiesel69 233]

Shell Rotella T1 SAE 30
 

[TunaSlayet 88]

So shell T1 SAE 30 it is. That is a very interesting and helpful point made about the horizontal placement of the cylinders. It never really dawned on me. I will do an oil change with the suggested oil, and try to keep consistent track of the oil consumption after a similar service cycle. Hopefully this will do the trick! 

Now as far as just pulling and cleaning the heads, I am sure I will get a variety of suggestions. I understand it will do nothing to help oil consumption, and it sounds like that is not even really an issue with the motor at this point, but I would not mind just having a look at the valves and cylinder heads to see how bad they are gunked. I just don't want to make things worse by tinkering, but I also want to take care of the engine properly. This will hopefully be a loader tractor soon, and I want it reliable for snow removal when I attempt to retrofit my 2 stage wh 44" onto the loader and ditch the bucket for winter months. 

[gwest_ca-(File Mod) 10,539]

Here is the Kohler operator manual for the M20
http://www.wheelhorseforum.com/files/file/4108-engine-kohler-magnum-m18-m20-om-5259002pdf/

If you study the oil containers you will see the Sx class listed on some diesel oils along with the Cx class. That's what we can use.

S is for spark engines burning gasoline
C is for compression engines burning diesel

Garry
 

[Brrly1 1,146]

Question, are parts available?? Rods, pistons, rings?? I heard that as of now they are not available any longer? Curious as to what you might know?

[Fordiesel69 233]

So shell T1 SAE 30 it is. That is a very interesting and helpful point made about the horizontal placement of the cylinders. It never really dawned on me. I will do an oil change with the suggested oil, and try to keep consistent track of the oil consumption after a similar service cycle. Hopefully this will do the trick! 

Now as far as just pulling and cleaning the heads, I am sure I will get a variety of suggestions. I understand it will do nothing to help oil consumption, and it sounds like that is not even really an issue with the motor at this point, but I would not mind just having a look at the valves and cylinder heads to see how bad they are gunked. I just don't want to make things worse by tinkering, but I also want to take care of the engine properly. This will hopefully be a loader tractor soon, and I want it reliable for snow removal when I attempt to retrofit my 2 stage wh 44" onto the loader and ditch the bucket for winter months. 

​

Question, are parts available?? Rods, pistons, rings?? I heard that as of now they are not available any longer? Curious as to what you might know?

I just did 2 more kohlers with this method:​


1.  Remove head and using a razor blade get as much off as possible.  Get a brass wire wheel for a drill and remove the rest, rinse with carb cleaner.  Make sure gasket surface is clean.
2.  Place piston to bottom of cylinder and tape the top of the piston to cylinder wall to prevent carbon from jamming into the groove.
3.  Decarbon the valves and deck surface, in addition to the ridge on the cylinder.  Use steel wool or corse sandpaper to really get the ridge clean, or I use the brass wheel on the drill.
4.  Vacuum or use compressed air to get carbon out of cylinder.  Remove tape.
5.  Apply a decent amount of grease to the lowest part of cylinder and move piston to top.  Wipe excess grease.
6.  Clean top of piston until clean.
7.  Begin to lower piston in very small increments and wipe away carbon ridges and grease.  Each time you do this, the grease left will be less.  It takes about 7-8 times.  Only move piston down 1/2" at a time and do NOT accidentally move it up.
8.  Oil the ridge slightly and reassemble with new gasket.

Optional step, dump seafoam into cylinder until piston has 1/4" of fluid on top of it, and let stand until level drops 50%.  Then vacuum the remaining fluid out paying attention to suck the ridge clean.  A junk shop vac or old Kirby exhausting to outdoors would be good.  I have an old hunk of junk Kirby that was missing the bag and just let it blow it into a vapor. 

[TunaSlayet 88]

Sounds straight forward. I will be ordering the head gaskets and valve cover gaskets next week. I think the worst part would be pulling the engine off the tractor. The rear cylinder on these is pretty tight on the console. Even if it is preventative, it seems like an easy way to just give the vitals an inspection. The manual states every 500 horse to replace the head gaskets and clean up the gunk, and I am at 1500 or so. I seriously doubt the po did anything like that. Well thank you agin to red square for another oil question solved! I will finish the post up in a month or so with some conclusive results on the oil, and the heads once I get them cleaned. 

Edited June 11, 2015 by TunaSlayet

[TunaSlayet 88]

The head gaskets, rings, and some wear stuff is still available but, a lot of parts are not. I wanted to add the optional oil filter kit, but parts  are not available. 

[TunaSlayet 88]

Just wanted to follow up on this one. Oil consumption is gone! I have rack about 10 hours, and it looks like the shell Rotella T1 did the trick. There is less smoke on start up, and none when the motor gets loaded. Thanks to all!