2004 Kohler ch20s. Is it going bad???

[Bbo44 7]

Hi all,

 

Was doing routine maintenance on my 520xi and when I drained the oil it did not look good (1197 hours total, less than 30 hours on oil). It seemed pretty shimmery.  Especially when you stir it. It swirls when you stir. A few small chunks came out too. Opened oil filter and the media was really clean and looked normal. No chunks in it. Bottom of filter definitely thicker with what seemed like tiny specs of metal. Because of this, I ended up buying a ZTR since I have 3.5 acres to mow.

 

I plan on selling everything (hopefully as a full package), but want to make sure the engine is definitely going bad or not before I do. I thought about running it till it dies, but the thing is way easier to move under its' own power. I am not the guy to sell a running/working tractor that has a going bad engine without telling the buyer. Otherwise, it runs great, mows great. Starts right up. No abnormal noise. Sounds healthy, feels healthy. I noticed a grey deposit on dipstick last year when Checked cold. Occasionally can have small miss-fire at low RPMs but it has done that for years. Doesn't smoke. I always used 10w-30 full synthetic in my ownership usually Valvoline or Pennzoil. Although the last time I used walmarts Full syn supertech. I've heard decent things about it, and know people who run it exclusively. So I can't blame it. Previous owner didn't take great care of it.

 

I am not super familiar with small engines. I've done stuff here and there, but have never killed one or taken one fully apart. Not enough experience to know how much metallic is too much. So what you think????? I think I know the answer... Just want to be Certain.. THANKS!

 

[1968Commando 73]

That oil looks a little milky to me it may have some water in it 

[JoeM 7,942]

Back in my bush mechanic days, I would take a drop of oil and place it on a white paper towel. Let is soak through and see what is left under a bright light. Magnetic is real bad, non magnetic is just bad. There should be no visible metal. 

It does look like it has water in the oil. A bush test would be a crackle test, heating up a plate above 250 and dripping a drop of oil on the plate. If it crackles (makes steam) there is water. If it is just oil it will just smoke. I could see water if that was a LXI water cooled. Kawasaki. But being air cooled (Kohler) and having water in oil would be a puzzle. 

The only real way to tell is send off a sample. 

I would run it and take another look at the oil after one mow. 

[Wild Bill 633 867]

11 hours ago, Bbo44 said:

A few small chunks came out too.

Use a magnet to see if the chucks are aluminum or not. Kohler Command camshafts are cast iron and are known to go bad.

[Bbo44 7]

19 hours ago, JoeM said:

Back in my bush mechanic days, I would take a drop of oil and place it on a white paper towel. Let is soak through and see what is left under a bright light. Magnetic is real bad, non magnetic is just bad. There should be no visible metal. 

It does look like it has water in the oil. A bush test would be a crackle test, heating up a plate above 250 and dripping a drop of oil on the plate. If it crackles (makes steam) there is water. If it is just oil it will just smoke. I could see water if that was a LXI water cooled. Kawasaki. But being air cooled (Kohler) and having water in oil would be a puzzle. 

The only real way to tell is send off a sample. 

I would run it and take another look at the oil after one mow. 

I did the paper towel thing and really don't see much. Looked like normal dirty oil. I dumped a lot on and let it soak though for the day. same thing. I ran a small magnet through the entire 2 quarts. There were some magnetic bits, but over a 1/4" round magnet it was barely covered and the bits seemed black.

Yeah, it is the air-cooled version so water really would be a mystery. It was always kept in a sealed shed and never sat outside. So the only way water would get in would be moisture, or from gas. I ran the same gas through all my stuff, and had no issue. I really think the water look in the oil is actually tiny metal flake. flake so fine that it wasn't filtered out by the media in the filter or the paper towel. It has a ton of shimmer (almost like super fine glitter) when you stir it up and shine a light on it. It is hard to capture it on camera. In HD video it is very shimmery. When I drained the oil into my oil jug, the bottom of it was thick and gray. I will have to try to do the crackle test. I save a little bit of the oil in a bottle before dumping the rest into a jug that already had old oil in it. I uploaded the full length of the video to Youtube unlisted so it would maintain video quality. You can really see the shimmer around the 18 second mark. Watch on YouTube and crank the quality up. For some reason this site destroys the quality even if you turn the quality up.

 

I would rather not pay for oil analysis if I'm getting rid of it anyways. I also bought a Zero Turn that cuts 45 minutes off my mow time. I guess I could Idle the 520xi for a decently long time and check the oil then. 

Thanks!
 

 

Edited yesterday at 04:44 AM by Bbo44
Added watch on youtube instead on this page

[Bbo44 7]

17 hours ago, Wild Bill 633 said:

Use a magnet to see if the chucks are aluminum or not. Kohler Command camshafts are cast iron and are known to go bad.

I did do this. There were a few ferrous bits on a 1/4" magnet when i ran it through the full 2 quarts. The magnet was covered on the one side but definitely not full. There were a few bigger bits. Weird they weren't in the filter. I did not know the command camshafts were a common failure.

[Bbo44 7]

On 4/28/2025 at 10:49 PM, 1968Commando said:

That oil looks a little milky to me it may have some water in it 

that's what I thought.... But it is an air cooled engine, always stored in a sealed shed and was never left out in any rain. when you stir it, with a bright light it is glittery though.

[1968Commando 73]

8 hours ago, Bbo44 said:

that's what I thought.... But it is an air cooled engine, always stored in a sealed shed and was never left out in any rain. when you stir it, with a bright light it is glittery though.

Is this oil old, even though it was stored in a sealed shed engines can still sweat and collect water from humidity and other odd ways regardless change the oil obviously and then maybe run it a hour and drop it and then see. If there is more metal in it

[Bbo44 7]

6 hours ago, 1968Commando said:

Is this oil old, even though it was stored in a sealed shed engines can still sweat and collect water from humidity and other odd ways regardless change the oil obviously and then maybe run it a hour and drop it and then see. If there is more metal in it

It isn't that old. I change it yearly. Every spring before I start mowing I change it. My log says I have about 29 hours on it since I changed it last. I noticed mid-late summer last year that when I checked the oil before starting it, it would have a grey deposit on the dipstick on the sides, and the rest would be fairly clean oil. I have never seen the oil like this though. At about 18 seconds in the video I posted above to youtube, you can see quite a bit of flake or reflection. In person it was more obvious.

But ya, I guess I will run it for a bit and drop a little oil out of it to see what it looks like. I'll just start it and let it idle while I mow with my ZTR.

[RED-Z06 2,479]

Oil has to periodically come up to full operating temp (for a while) to boil off accumulated condensation, every time and engine gets warmed up then allowed to cool, youll get some moisture.  When i worked for a dealer, equipment was put out and taken in every morning/evening and it wasn't uncommon to get a pint of accumulation after a few months, the oil would run out like a milkshake.  Its probably fine, you'll get wear, you'll get metal..

[Bbo44 7]

2 hours ago, RED-Z06 said:

Oil has to periodically come up to full operating temp (for a while) to boil off accumulated condensation, every time and engine gets warmed up then allowed to cool, youll get some moisture.  When i worked for a dealer, equipment was put out and taken in every morning/evening and it wasn't uncommon to get a pint of accumulation after a few months, the oil would run out like a milkshake.  Its probably fine, you'll get wear, you'll get metal..

It came up to full operating temp at least once a week. And ran hot for nearly 2 hours every mow. Hot as in temp gauge was teetering towards the too hot side. I never noticed anything before. You think it's fine then? I mainly don't want to screw someone over when I sell it. Last year was the first time I noticed a gray deposit on the dipstick every time I checked it before running it. And this is the first year I noticed the oil looked that bad. I normally didn't look too hard but never had a reason to really. Once I saw how shimmery and metallic looking it was, I went and bought the ZTR.

[RED-Z06 2,479]

1 hour ago, Bbo44 said:

It came up to full operating temp at least once a week. And ran hot for nearly 2 hours every mow. Hot as in temp gauge was teetering towards the too hot side. I never noticed anything before. You think it's fine then? I mainly don't want to screw someone over when I sell it. Last year was the first time I noticed a gray deposit on the dipstick every time I checked it before running it. And this is the first year I noticed the oil looked that bad. I normally didn't look too hard but never had a reason to really. Once I saw how shimmery and metallic looking it was, I went and bought the ZTR.

If thats metal, I'd be shocked if it hadn't already locked up or started knocking violently.  Does it still start and run fine?  No oil pressure light?

[Bbo44 7]

26 minutes ago, RED-Z06 said:

If thats metal, I'd be shocked if it hadn't already locked up or started knocking violently.  Does it still start and run fine?  No oil pressure light?

Fires right up. Sounds no different than it has the last 5 years. This was after I drove it from my garage to the back yard so it was slightly warm. But even today I started it, full choke, minimum throttle and it still fired right up. Full RPM sounds fine too. Engaged PTO seemed to lose RPM a little, but engine was basically cold and everything is due to be greased. Muffler insides grenaded itself a long time ago.

[JoeM 7,942]

Having four of those running, with hours in the 750 to 1100 range, I have not seen oil look like yours. That metal is an issue. I would run it to move it around and tell the next owner and let them deal with the problem.