Kioti CK20 Blowing white/blue smoke

[brkdrvr]

Coolant temp was slightly elevated prior to the problem (coolant definitely did not vent into coolant over-flow). I have run temp at a more elevated level (3/4 of gauge+) before when mowing tall grass/brush and had to clean out radiator screen which immediately resulted in dropped temp. Coolant looks clear and green at this point with no evidence of contamination. I will do the coolant test and post later today.

 

[MotorSeven]

I'm thinking head gasket too.

 

[brkdrvr]

OK, I started tractor up drove on the trailer (it was still smoking quite a bit). Brought it home, pressure washed it off and started it up & let it run for ten minutes at idle with the radiator cap off to look for bubbles, it's hard to see bubbles w/running diesel, the coolant shaking quite a bit, stuck a clean paint stir stick in opening to settle down and see no bubbles or evidence of contamination. The tractor is now running very cool (below the normal mark on gauge) and smoking a lot less, almost normal. Almost no smoke at idle and just noticeable at max throttle which yields about 3000 RPM (its fairly windy here but there id definitely less smoke. Hydraulic fluid is the only thing low, (one of the FEL quick releases has been sticking and losing quite a bit of fluid several ounces) at each disconnect. I am now idling w/rad cap on to see if temperature and/or smoking increases, if not I am really stumped. Can hydraulic fluid get into combustion? Will run out to see if I can find hydraulic fluid on Sun maybe at Walmart.

 

[MichiganIron]

Just a couple suggestions:

It's safer to test for exhaust pressure in the cooling system by first making sure your radiator coolant is at the proper level, and that the reservoir is about 1/2 full. Start the tractor and let it warm up. Remove the RESERVOIR cap and look for bubbles. If pressure is building in the cooling system, it often shows up as continuous bubbling in the reservoir tank.

Pressure test the cooling system. Test kits aren't expensive and can show pressure leaks in the system. This would usually indicate a failed head gasket if the pressure doesn't hold and no coolant leaks are seen. You can then drain a little oil and look for coolant.

Compression test the engine. The smoke you have described can indicate low combustion compression and/or coolant in the combustion chamber. (head gasket / warped head)

The above test are fairly simple and will go along way to indicating where the issue is. If the smoke was dark, we would pop test the injectors.

 

[brkdrvr]

Have now run the tractor for fifteen minuted and no smoke or bubbles in the over flow canister. I need to top up hydraulic fluid anyone know if Walmart carries the right stuff for a CK20 HST?

 

[SSdoxie]

I haven't looked myself but others no here say Walmart handles the Shell Dontax or now renamed Spirax. If the smoke is gone now that you have ran it with some fuel conditioner in it, I would guess it was some bad fuel. You might want to rinse that can out with a little fuel then hang it upside down to let dry for a day before reuisng it.

No, there is no way for hydraulic fluid to get directly into the cylinder or fuel. Hydraulic fluid can get into the oil pan & mix/overfill the engine oil level if the seal on gear pump fails.

 

[VictorW]

If you do have to pull the head, you'll need new head bolts.
Here's the injector for $147: http://www.michironandequip.com/pag...100A-E130/01-01|~CK20S-M-ENGINE/0101CK20S0165
You could also try a Bobcat dealer for price. Yours would be the same as a CT122.

 

[ritcheyvs]

The newer Daedong manuals (like the EX35-50 manual on the Australian web site) do a good job explaining the fuel injection system. On the other hand, my DK45S service manual is pretty-much useless in that regard. In any event, these tractors use a Bosch inline injection system similar to old (pre-electronic) Mercedes Diesels.

The injection pump uses one plunger/cylinder to feed each cylinder in the engine. Each plunger and its cylinder are a matched set with very close tolerances. A small gear-driven cam shaft moves the plungers up and down; this creates positive-displacement pumps that can produce high pressures (well above 2000 psi). The plungers are rotated in unison to control the amount of fuel pumped on each stroke; groves machined into each plunger "vent" the pressure at a specific point in the stroke as determined by the plunger rotation angle. The rotation angle is controlled by the toothed rack that meshes with a gear on each plunger. So the start of injection for each engine cylinder is controlled by the cam and the rack controls all plungers to inject the the same volume of fuel.

The injectors are poppet valves that open at a preset pressure (about 2200 psi) to create a finely atomized cone of fuel spray. They can fail by leaking or dripping, opening at the wrong pressure (set by internal shims), or producing a poor spray pattern, jetting is particularly bad. You can test injectors with a pop tester which allows you to gradually increase pressure while looking for leaks up to the "pop" pressure where you can see the spray pattern. Caution: this spray can penetrate skin and Diesel is really bad inside your body. I presume these injectors can be disassembled for cleaning (requires very fine wires) and rebuilding (replace nozzle body and needle valve and re-shim) assuming a parts source and torque specs.

Assuming you isolate the problem to injectors, maybe you have a nearby Bosch Diesel shop that can test them for you. On the other hand, many Diesel Mercedes owners report excellent results after running a can of Diesel Purge through the system. Or maybe you just had a carbon buildup that since cleared itself; we should all be so lucky.

 

[Coyote machine]

Coolant temp was slightly elevated prior to the problem (coolant definitely did not vent into coolant over-flow). I have run temp at a more elevated level (3/4 of gauge+) before when mowing tall grass/brush and had to clean out radiator screen which immediately resulted in dropped temp. Coolant looks clear and green at this point with no evidence of contamination. I will do the coolant test and post later today.

The coolant reservoir tank should have a min/max mark on it and should always contain fluid to the min mark when cold.
Sounds like you may have been allowing the engine to get hotter than normal by allowing grass to clog the screen and by not keeping the overflow tank filled to the min mark. This is not criticism, just reference for the future with your CK-20. IF your engine was running at 3/4+ while working hard in hot weather this can be enough to push a marginal head gasket/ head to move toward failure over time. Diesels run notoriously COLD in general and unless a component like a thermostat is faulty or a radiator screen is blocked they don't tend to go above normal on the gauge. I know its difficult to keep the screen clean but when you're taking a drink or bathroom break this is the time to do it; let the engine cool down at idle. Also let it run for a short time after working it hard to allow it to dissipate heat rather than just shutting her off. And make sure your fan belt is good and snug especially in hot weather.
I'm inclined to think you are experiencing at least an overheat problem, and if nothing else can be attributed to the recent situation, you may want to check the thermostat's operation. It could be intermittent and sticking in the hotter weather. You could also have a simultaneous bad fuel or intermittent sticking or poor spray pattern injector, though unlikely.

 

[brkdrvr]

Well prior to pressure washing I lowered the mower deck and used the lowering speed know to let the unit drop slowly ( I don't normally fiddle w/the knob but in reading over the manual I though I would adjust the 3PH lowering speed). I topped up the hydraulic fluid and now have no hydraulics to the 3PH or the FEL. I used both to raise deck and FEL to get on trailer. Trans and PTO work fine. I am also getting no smoke in the exhaust or bubbles in the coolant. I'm wondering now if this entire problem was related to the hydraulic pump. The #pt hitch lowering speed adjustment know is now very loose and does not feel right. Any ideas?