overheated diesel (Kohler)

[clytle374]

overheated diesel (Kohler) video

Had a mouse build a nest in the shroud and over heat the engine bad enough to melt the fuel tank.
seems a little low on compression now. wondering if I might get lucky and it only cooked the rings. anyone have any experience with these being overheated?
thanks
cory

 

[jd4310man]

It might have heated the oil enough to gum up the rings and not allow them to seal properly. Thats a good case scenario. Worst case would be scored or warped block or head. Id drain the oil and add some sea foam and see if that does anything. If not it might require a tear down to see if there is engine damage.

 

[clytle374]

Thanks. I wasn't there when it happened, it was a surprise when I got home. They said it was running fine while they were cutting hay with the disk mower, then they noticed that it was leaking fuel. Both the mounts on the right side of the tank were melted. The mounts are solid steel stand offs that bolt into the block and head. Love to know what the melting point of that plastic is.

It seems low on compression when I pull the rope. I also wonder if that isn't partly the oil cooked out of the rings from the heat. Irritating part is we even have the screen to keep the grass out of the engine and wipe it off constantly to keep from overheating the engine. Somehow a mouse got inside and the result was the right side passage was completely blocked.

I'll get some seafoam soaking on the piston overnight. Can't even test run the motor without rigging up a fuel tank.
Thanks
Cory

 

[clytle374]

Put some seafoam in the cylinder last night, this morning I drained the oil and turned the motor over slowly a few dozen times. I flushed the crankcase out with a bit of oil and put in new oil. Put the engine back together with the JB welded fuel tank. Had enough compression to about rip my arm off, and started the first time I got it over center. Smoked pretty bad at first.

Now it runs but misses at higher rpm. Still a little bit of smoke, more when it misses. Oil ring maybe? Or injection problem? It runs better now than when I first started it. I'd like to know how it runs under a load, but hate to keep running it. Removed the oil cap and there is enough pressure the cap won't sit on the hole, but not smoking out of the cap. Should I tear it down? Not sure what to think at this point.

Here is a video of it running.

http://youtu.be/6CMCKBhgBMo

 

[clytle374]

More info. Sister heard it and said it started missing like that when she shut it off and found it was low on fuel then found the leak. I really wish people would tell me what really happened, last time it was running fine when she shut it off. In my business of repairing machines I often get 2-3 stories of what happened.

Now for a weird fact. I pulled the valve cover and found that the exhaust valve opens just slightly after the intake valve. I also noticed sometimes it has more compression than others. Makes me wonder if there is a compression release problem. Or if the hydraulic lifters are messed up.

Cory

 

[leonz]

More info. Sister heard it and said it started missing like that when she shut it off and found it was low on fuel then found the leak. I really wish people would tell me what really happened, last time it was running fine when she shut it off. In my business of repairing machines I often get 2-3 stories of what happened.

Now for a weird fact. I pulled the valve cover and found that the exhaust valve opens just slightly after the intake valve. I also noticed sometimes it has more compression than others. Makes me wonder if there is a compression release problem. Or if the hydraulic lifters are messed up.

Cory

Hello Cory,

I would send Joel at earthtools(walkbehindtractorman) a PM and ask about this issue.

I worked on much larger air cooled indirect injection Duetz engines for a living and it looks like
you need to have a bit of work done. A plugged cooling system on an air cooled diesel like an
air cooled gasoline engine is bad news simply because of reduced cooling air.

Saying that the other issue is how much warranty coverage you have left, if any.


You might want to consider a Hatz air cooled diesel replacement for it if it out of its
warranty period. The Hatz family has been making small air cooled diesels for over 50 years plus.

I am unsure if the Kohler is a Lombardini in Kohler Paint or an actual Kohler engine.

 

[clytle374]

being that it starts easily I don't think it's internally damaged. I never pull started the engine before this spring when the battery died so I never got used to the compression release to say for sure about it's compression. sometimes it is good and others it's really low. it seems dependant on pulling speed.
after thinking about it really seems like a fuel problem I checked and the filter and lines are full of junk. waiting on Joel to get back to me about a tank, lines, filter
it's a Kohler paint Lombardi. something else I learned is that it has an over temp sensor in the oil gallery. I know it was the cylinder getting hot, but that does make me feel a little better.
cory

 

[jd4310man]

clytle374:

If you had the fuel system apart I would definitely say that you have air in the fuel system, it may take some time to get all the air bled out. From the sound of your video, Its missing at high idle either their is air in the lines or the engine is not warmed up yet. These small air cooled diesels take a bit of time to warm up and they will miss at high idle when cold. A little blueish or white smoke is normal when cold but if its still blowing blue smoke when warmed up, there might be some damage done. Before you go and tear it down, run it for a while and do some work with it, That will let you know if there is something wrong or not. These European diesels are quite tough and can take a beating. Its not good to take it to the braking point either seeing how expensive it is to fix one. Good luck!

 

[Bentleg]

Our mice would rather live in my 5 horse B & S than anywhere. I've been using one of those plug in mouse repellers laying right on the sheet metal.

 

[clytle374]

I'm waiting on a fuel filter, lines, and tank for more testing. Either plastic dissolved in the fuel and went through the filter, or the lines are breaking down. Kinda feel stupid that I didn't catch on earlier. It was classic fuel started diesel symptoms. Either way the filter is plugged and I can't find the spare I know I have.

As far as the compression, it has to be the compression release. We never pull started it before this year so I'm not familiar with it. But according to the service manual the compression release is on until the engine hits 300 rpm. It's never done that, we always had to pull it slowly to compression then "go for it" so to speak. It had compression when I was turning the flywheel be hand. Anyone care to describe the behaviour of theirs?
Thanks
Cory