Smoking Diesel

[Tractor Nubi]

I have a dong feng tractor from China. I purchased it last year and it has had its first 50 hour servicing. The fuel filter that I removed had a lot of particulate matter in it and around the rim. I have run it about 15 hours since the servicing and all was well until... it started to smoke blue smoke and power decreased. When I increased the rpms, the smoke turned to white. It all smelled like diesel. I let it cool and checked all fluid levels and all are good and clean. Air filter is still reasonably clean. Ran engine for a few minutes with out air filter and smoke did not dissipate. I had a load of wood chips dump on the tractor minutes before the smoking and surmised that some got into the exhaust. I removed the exhaust and nothing in it. I ran the engine with out the muffler (just the manifold connected) and the smoke was blue and did not change to white (when rpms were increased). There was what looked like small fuel droplets in a spray pattern from the manifold onto the hood. I reinstalled the muffler and ran it and blue smoke changing to white when rpms increased (uncombusted fuel in muffler) resumed. Any thoughts? I haven't exactly babied it (rpms no higher than 2200) but I am not sure what others consider running hard. Could an injector be clogged? Tractor is run for at least 2-4 hours 2-3 times a week.

 

[john_bud]

My guess is that you have an injector stuck open or clogged and not atomizing well. Can you take off the exhaust manifold and see if there is one port that is the location of the liquid diesel? That would show a single injector is at fault.

If all are wet,then the fuel pump may not be making enough pressure to atomize the fuel. Could be a clogged filter (bad fuel can do it QUICK) or the pump going out.

I would change the filter and add some diesel cleaner. Powerservice in the silver bottle or Howe's or similar. If that fixes it, then you are good to go. Otherwise, you need to dig deeper. If it's still under warranty, you may want to take it back to the dealer before doing anything.

jb

 

[RoyJackson]

Due to the low hours, I wouldn't remove any components at all. Let the dealer do that
I am assuming this machine had a warranty and is still in warranty.

If there is no warranty remaining, try the filter first and new fuel (you could have got a bad tankfull). If that doesn't clear up the problem, try an injection cleaner.

I'm a solid proponent of trying all options prior to removing any components, including something as simple as an exhaust manifold. If it comes to removing the manifold, John_bud's got the correct procedure.

 

[Farmerford]

I agree with John Bud that a new filter and diesel cleaner is in order just to eliminate the easy possibilities, and I agree with Roy Jackson that you shouldn't take parts off if it is still under warranty.

But I think your problem may be sticking piston rings and/or glazed cylinder walls. If you have been careful not to exceed 2200 rpm for 65 hours I suspect you also have not put a substantial load on the engine either. The rings may not have seated to the cylinder walls, so that you have both lower than ideal compression and are using a little oil as it escapes past the rings. If you run it long enough like that the rings may begin to stick in their grooves and the cylinder walls will glaze over with carbon.

If so, it needs a good load on it for several hours fairly quickly before the rings stick and the cylinder walls glaze with carbon beyond recovery. Harrowing, plowing, bush hogging in heavy grass or brush, or something like that is best. If you don't have those chores, the next best thing is to accelerate from minimum speed to top speed up a long hill in top gear, so that the engine strains to increase rpm for as long as possible. The rings need enough heat to burn away the oil film and enough pressure to make the rings and cylinder walls come into contact long enough to wear away the high spots and let the rings conform to the cylinder walls. It may take several trips up the hill before you notice a difference.

 

[J_J]

I have a dong feng tractor from China. I purchased it last year and it has had its first 50 hour servicing. The fuel filter that I removed had a lot of particulate matter in it and around the rim. I have run it about 15 hours since the servicing and all was well until... it started to smoke blue smoke and power decreased. When I increased the rpms, the smoke turned to white. It all smelled like diesel. I let it cool and checked all fluid levels and all are good and clean. Air filter is still reasonably clean. Ran engine for a few minutes with out air filter and smoke did not dissipate. I had a load of wood chips dump on the tractor minutes before the smoking and surmised that some got into the exhaust. I removed the exhaust and nothing in it. I ran the engine with out the muffler (just the manifold connected) and the smoke was blue and did not change to white (when rpms were increased). There was what looked like small fuel droplets in a spray pattern from the manifold onto the hood. I reinstalled the muffler and ran it and blue smoke changing to white when rpms increased (uncombusted fuel in muffler) resumed. Any thoughts? I haven't exactly babied it (rpms no higher than 2200) but I am not sure what others consider running hard. Could an injector be clogged? Tractor is run for at least 2-4 hours 2-3 times a week.

I had a similar problem several years ago, on my Kubota. White smoke, dark smoke, and engine rattle . Checked everything like you did. Took off the air cleaner and it ran good , got new air filter, same problem. Looked through the intake tube, was dark, so I stuck a wire with a hook in the tube, and guess what, pulled out a rat nest which was blocking off the air. Cleaned that out and has run good with no more problems

 

[oldmech]

My opinion. injector trouble. Open injector by dirt in seat. May be just cleaning. Find the bad injector. Good Luck !Oldmech

 

[oldmech]

Also . Clean drain the fuel system. Line fuel filter etc. Good Luck! Oldmech

 

[D7E]

Does it use oil or water , mix fluids or lack power , if not Sounds like it's just coked up, stuck rings glazed cylinders Not working an engine hard can be as bad as too much hard work .If i run my 135 hp tractor on a log splitter for a week it blue smokes terrible but 2 hours hard pulling on a cultivator turns that smoke black again .
Give it a good hard workout ,

 

[RonMar]

Any chance you got water into the fuel system?

 

[Tractor Nubi]

I want to thank you all very much. This site has been terrific for support. I am not a mechanic so I took the easy road first and changed the fuel filter and added injector cleaner and ran the crap out of the engine for 4 hours. It runs cleaner (absolutely no colour to the smoke) than I have ever seen.
J