My father picked up a
M5700 this weekend. Overall its in nice shape, but we have a couple things we are trying to figure out.
Most importantly, it has a 'knock' to it, that doesnt sound like a rod knock, but is something that does need attention, and we arent quite sure what it is. Seller had suggested it was likely an out of adjustment rocker arm. today I took the valve cover off and checked all the rockers, found one slightly out of spec, but it did not cure the problem. Since it was still making the noise, i ran it some with the valve cover off, holding each rocker tight against the valve, and then the push rod, testing to see if I could alter the noise. it had no effect.
The next thing i tried, was cracking each injector to try to isolate it to a cylinder (and maybe also an injector). On cylinders 1-4, it seemed to have no effect on the noise. #5 it did sound like it went away mostly (if not all the way, its hard to tell for sure)
I dont suspect a rod bearing issue, as they usually have some variation with RPM. This is very consistent.
Here is a video of it running and the noise is very clear in the video:
Kubota M5700 'knock'? - YouTube
Looking for ideas! Tractor has just under 2000 hours on it. I drove it home (almost an hour drive) and it ran fine, has plenty of power etc. I am seriously thinking maybe a bad injector? or worse, maybe a piston pin? It does sound more top-end than bottom-end in the engine. We did pour some fuel injector cleaner (diesel kleen brand) and ran it for probably 45 minutes doing light duty loader work after. No change. he is thinking possibly a collapsed lifter?? and is planning to try some Rislone in it to see if that helps. I would think a collapsed lifter would be obvious with the valve cover off (especially when running!)
Other questions....
The tire sizes seem off. The rear has 16.9-24 on it (R4 industrial tires). I cant remember what the fronts are at the moment, but I believe they were on a 20" rim??
Where might I find a drawbar for it? it is among the missing, and is something we really could use. Also could use some 3pt inserts, as the ones on it appear to have been broken and re-welded? or at the least bent? The angle on them seems odd.
We are missing a couple other things that would be nice to put back on, like the mirrors (both inside and out), and it seems to have maybe had a dome light inside the cab?
Final thing... what RPM is this supposed to idle at? Seems a bit high if you ask me....
Thanks
Mike
