2004 Kubota HST L5030 knock and blue smoke

   / 2004 Kubota HST L5030 knock and blue smoke #1  

Axlebender

New member
Joined
Jul 28, 2016
Messages
7
Location
Gravette
Tractor
Kubota L5030
TBN group, last night I was idling along on the tractor when it suddenly belched a bunch of black smoke out the exhaust, then the engine coasted down in power till it died. Battery light was only light lit. It needed replacing anyway so I dropped a new one in it today, then attempted to start it.
It turned over and over puffing blue smoke. On the third try it was turning over faster and faster and finally started firing, idling fairly smoothly with a knock. As it warmed up it was idling more smoothly but pushing a lot of blue smoke.
Shut it off, checked fluids again, no antifreeze in oil, oil mid full mark.
Fired it up again same process. 3 extended starting cycles before it fired up with lots of blue smoke. Operating temps were normal, with a very disconcerting occasional metallic clang.
I am no mechanic, but can perform basic checks prior to dealer trip so any suggestions would be appreciated.
Use rotella oil, wix filters, Opti Lube in every tank. Just under 1000 hours.
 
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   / 2004 Kubota HST L5030 knock and blue smoke #2  
It doesn't sound good. I would stop attempting to start it until I could understand what metallic sound you're hearing.

Sorry you are having trouble with it. Maybe start with a compression check across all cylinders.
 
   / 2004 Kubota HST L5030 knock and blue smoke
  • Thread Starter
#3  
Yeah, I don't think it's going to end well but hoping for a simple fix.
 
   / 2004 Kubota HST L5030 knock and blue smoke #4  
Blue smoke is burning oil. Impurities in engine oil tint smoke blue. So that likely means rings, or valve seals are shot, possibly something else between the piston & crankshaft.
 
   / 2004 Kubota HST L5030 knock and blue smoke #5  
I'm no diesel guy by any means but could a bad batch of fuel cause this issue? I know here they treat the diesel for winter use.
 
   / 2004 Kubota HST L5030 knock and blue smoke
  • Thread Starter
#6  
I thought the blast of black smoke might be an injector failure. Not looking good from a "minor issue" angle.
 
   / 2004 Kubota HST L5030 knock and blue smoke
  • Thread Starter
#7  
I wish!! I buy in bulk and treat every tank so not a high probability.
 
   / 2004 Kubota HST L5030 knock and blue smoke #8  
To heck with smoke -- with knocks and metallic clangs you have some sort of major engine internal issue. Straight to the diesel mechanic if it were mine.
 
   / 2004 Kubota HST L5030 knock and blue smoke
  • Thread Starter
#9  
I think that's going to be the best course of action. We have a good local dealer, Springdale Tractor. Guess I'll go load it up.
 
   / 2004 Kubota HST L5030 knock and blue smoke #10  
Had the same symptoms on a smaller tractor many years ago.

It was expensive, ended up with a new motor, wish you better luck.
 
 
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