Up in smoke !

[jetson145]

Hey guys
New to the forum and Kubotas. I have a 2013 L3800 HST (w/FEL) that I just purchased with 72 hrs. Tractor was like new and just out of the bumper to bumper warranty. I noticed a minor fluid leak coming fron the steering box, but other than that the thing is perfect. At one point while pulling my box trailer up my semi steep driveway I noticed some rev-up of the engine and white smoke belched from the exhaust. It quickly went back to normal. Mechanic friend of mine indicated this could be a fuel issue as there was still some of the original fuel from the previous owner.

Yesterday was running my new Woodmaxx chipper and after about 30-40 min of normal operation the engine started to over-rev big time, so I killed it with the ignition. Once again it belched white smoke. This time it wouldn't restart.
I had to leave as it was Valentine's Day and we had some plans. Fast forward and I got her running this morning, turns out the PTO cable was sticking and not disengaging.

So I'm wondering about the over-rev/smoke issue, anyone have any ideas. The 50 hr maintenance was just completed so all the fluids are pretty fresh. I noticed that the trans/hydrolic fluid looks "milky" in the sight window, is that normal. The tractor now starts and runs normal again? Ran the chipper again for a few minutes and all seems normal. Sure would like some input. Thanks in advance for the help!!!

 

[Bulldog]

First thing that came to mind is water in the fuel. Might try a new fuel filter and add some fuel conditioner to the tank.

 

[Sammy3700]

Have not had the problems you are speaking of however, if the oil is milky you most likely have water in the oil. May be from siting on dealers yard?

 

[jetson145]

So, found the power steering leak. Was just a loose fitting on the steering box. Took a closer look at the trans sight glass and the fluid is not milky. There is a white/yellow backer behind the glass for easier viewing. So that's all good. Fuel filter looks good. Going to get a new one and some fuel stabilizer.. So hopefully that will solve the over-rev/smoke issue.

 

[Dave_eng]

Just remember that diesels don't care where they get their fuel from.
An open gas can near the intake on a hot day can cause the engine to inhale the gas/hydrocarbon and run away. An example: tankers which deliver gasoline to gas stations can have their engines self destruct as there is no way to stop them if they start inhaling fumes. Wise people direct a Co2 fire extinguisher into the intake to stop the engine before a rod lets go.
Old engines with worn out rings and lots of oil getting to the combustion chamber can start running on the crankcase oil.

The fact that your engine speeds up unexpectedly concerns me and prompts me to suggest you look for other sources of fuel. A crankcase vent hose connected to the engine intake can be a problem if the oil level is too high.

Dave M7040

 

[North Idaho Wolfman]

I'm thinking you have contaminated fuel, possibly with gasoline.
I would dump the fuel and refill it with new good fuel, I would also treat the fuel with Stanadyne.

 

[coachgeo]

Over rev. yikes don't like that. Any of the things mentioned thus far don't explain over rev. except ingesting fumes as mentioned.

If it is still in warranty.... then don't touch it. Send it back. some how it is ingesting some other oil source as additional fuel (engine oil or hydraulic oil) or something is causing the IP to feed more fuel.

I'ld demand a replacement tractor. Maybe I'm overreacting but I've seen first hand a run away diesel engine.

 

[Daren Todd]

A pin hole air leak after the fuel pump can cause an over rev as well. Come across it a couple of times. Both times it was an o'ring in a filter base that was between the fuel pump and injection pump.

 

[coachgeo]

A pin hole air leak after the fuel pump can cause an over rev as well. Come across it a couple of times. Both times it was an o'ring in a filter base that was between the fuel pump and injection pump.

Darren and Wolf know way more than I do. Hope that is it.

 

[jetson145]

Dave
It is interesting that you mention the oil level and crankcase vent. I was checking all the fluids and noticed the oil level seemed high. The level on the dipstick was about a 1/2" higher than the second drilled hole. Manual shows oil level to in between the 2 drilled holes. I didn't think to much about it as this service was just done by the dealer (by previous owner).Guess i should get this right to eliminate the chance this is the additional fuel source. Thanks for the comment.

The tractor had about two gallons of fuel in the tank when I picked it up from the previous owner. I stopped at the station and filled it up on the way home so "most of the fuel is fresh????