Strange oil usage.

Big Jon

Member
Joined
May 4, 2013
Threads
3
Messages
19
I've got a 48" Cub Z Force S with a Kohler Command CV680 engine with just over 150 hours on it. The mower is run on a fairly flat lawn & the only time it's run in any kind of dirty conditions is in the fall when I mulch leaves with it. It has never used any oil and gets a complete service & cleaned up every November before I put it away for the winter. It's a '13 model, so it's being run less than 20 hours per year. It has always had a mulching kit on it. It gets blown out after every mowing and the air filter has never gotten dirty. The only thing I did different last fall when I put it away was when I filled it with gas and poured Sea Foam in the gas tank, I added an extra 2 or 3 ounces just to empty the bottle.
This spring when I started it up the first time it smoked. A lot... As soon as the motor warmed up it quit smoking, ran fine, and had good power, just like it always has. I wondered at the time if it smoked so bad when I started it because of the extra Sea Foam I had added when I stored it for the winter. I idled it down a couple of times to open & close gates & each time I throttled it back up it would blow out a cloud of gray smoke for a few seconds and then clear up again. When I finished mowing I let it cool down & then blew it off with my leaf blower like I've always done & then put it back in my shed. I checked the engine oil the next day and had to add 6oz. of oil. (Kohler 10W30 Synth. blend, which is the only oil it's ever had) Once again, I've never had to add a single ounce over the past 8 years. I did check the muffler tip & it was typically clean, with just a bit of dry, gray residue on my finger.
I decided since there was no noise, knock, or power loss in the engine, to mow at least one more time before checking with my dealer about what was going on. The second mowing was an exact replay of the first except instead of using 6 ounces of oil it only used 2 ounces. I decided to keep using it. The 3rd mowing, it acted exactly the same as the first 2, except that I had to add about 4 ounces of oil. The muffler tip was black when I checked that time & slightly moist.
After that I checked with my dealer and one other dealership & told them what happened & both of them suggested I keep using it & see if it gets any worse before bringing it in to get checked. One of them suggested possibly checking valve adjustment. The other dealer said it has hydraulic lifters & won't need the valves checked...
I mowed for the 4th time today & it's another repeat of the first 3 mowings. Lots of smoke on startup, then running clean with great power & no unusual engine noise. I got puffs of gray smoke each time I would idle it down & then go full throttle again. I did notice today that after letting it cool down for 10 minutes and then blowing it off like I always do, that the red oil light cycled on & off after I started it to put it back in the shed. It went out & stayed out when I throttled it up. I have not noticed it coming on while mowing, but I suppose it's possible... This has always happened occasionally for a few seconds when I start the engine cold. I guess it's time to get it checked out. Any thoughts before I haul it in?
 

Paul54

Member
Joined
Aug 10, 2017
Threads
0
Messages
16
Almost sounds like after running and then shutting down the breather Reed is not seating fully and allowing the oil to puddle on top of the piston and when you start it up it blows blue white smoke and then settles back , make sure you are checking oil level correctly - it should be with the cap just resting on the filler tube threads, not screws on . what oil are you using?
sounds like breather Reeds are not allowing c/case vacuum on piston up strokes ( exhaust /compression)and pressure bypass on piston down strokes, (power/intake) can't be totally sure your engine may have breather in the valley between cylinders or under each cylinder head in between the lifters
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
79
Messages
10,254
Almost sounds like after running and then shutting down the breather Reed is not seating fully and allowing the oil to puddle on top of the piston and when you start it up it blows blue white smoke and then settles back , make sure you are checking oil level correctly - it should be with the cap just resting on the filler tube threads, not screws on . what oil are you using?
sounds like breather Reeds are not allowing c/case vacuum on piston up strokes ( exhaust /compression)and pressure bypass on piston down strokes, (power/intake) can't be totally sure your engine may have breather in the valley between cylinders or under each cylinder head in between the lifters
Just wondering how you can explain this theory? Especially since the breather has no direct connection the piston.

It is more likely oil seeping pass the piston rings from being overfilled or it even be a bad head gasket and/or warped head, or valve stems seal.

Just to note I have brand new Kohler engines to smoke at start-up.
 

slomo

Lawn Addict
Joined
Jul 14, 2019
Threads
76
Messages
4,704
Anyone have a short-hand summary of the issue? Low hours, never smoked, poured in Seafoam, now it has lung cancer, dealer looked at it - all good even smoking??

Deduced down, Seafoam destroyed the engine.

As Guyina4x4 said, head gasket check, piston rings, crankcase vent hose should be inspected.

slomo
 

7394

Lawn Addict
Joined
Sep 5, 2014
Threads
84
Messages
4,709
I don't think the Seafoam is the culprit. I have been using it since I was a kid & my Dad used it long before he turned me onto it, some 50 yrs ago.
 

slomo

Lawn Addict
Joined
Jul 14, 2019
Threads
76
Messages
4,704
You know how these small engines make a lot of carbon? And that Seafoam dissolves said carbon? Which means all that hard grit is now inside the bore, piston rings, valve guides and so on? Puts a lot of wear on an engine. Ever wonder when you remove a head, you see big bore scratches? That hard carbon you have to use a hardened metal scraper to remove gets in places where it shouldn't be.

None of the small engine manufacturers recommend Seafoam for either fuel or oil mixes.

What is recommended is de-carbonizing your engine at periodic intervals. It's in every small engine manual I've seen.

slomo
 
Last edited:

Scrubcadet10

Moderator
Staff member
Joined
Sep 24, 2017
Threads
250
Messages
6,441
Elbow Grease works good for removing carbon, don't even have to mix or measure in the oil or gas.
 

ILENGINE

Lawn Pro
Joined
May 6, 2010
Threads
39
Messages
9,956
You know how these small engines make a lot of carbon? And that Seafoam dissolves said carbon? Which means all that hard grit is now inside the bore, piston rings, valve guides and so on. Puts a lot of wear on an engine. Ever wonder when you remove a head, you see big bore scratches? That hard carbon you have to use a hardened metal scraper to remove gets in places where it shouldn't be.

None of the small engine manufacturers recommend Seafoam for either fuel or oil mixes.

What is recommended is de-carbonizing your engine at periodic intervals. It's in every small engine manual I've seen.

slomo
My local Kohler distributor not only sells Seafoam but recommends it use.
 

slomo

Lawn Addict
Joined
Jul 14, 2019
Threads
76
Messages
4,704
My local Kohler distributor not only sells Seafoam but recommends it use.
A local Kroller distributor makes NOTHING. They SELL slash distribute everything they can. I bet they have a display of that wonder juice by the cash register. LOL

slomo
 
Top