M100XDTC "cold" Start blowing white smoke and misses

[andyman]

I'm no diesel expert so this may be a very basic question and a non-issue to the experts. I apologize in advance if it is. I purchased an M100XDTC brand new in 2013. It currently has around 300 hrs. on it. "Cold" only refers to being started after the engine has completely cooled. We've experienced this issue in temperatures ranging from 20 F to 65F.

The trouble I have is the tractor "cold" starts and idles fine. However, if you try to advance the throttle past idle, it misses and blows white smoke. You can reduce the throttle and it idles fine with no smoke or miss. If you try to advance the throttle again within 1-2 minutes, it will miss and smoke. Once the tractor has had time to warm a little, the problem goes away. You can shut it down and restart with the engine still warm and there's no problem. If you let the engine cool completely and then do another "cold" start, the problem will occur in the same manner. Here's a link to the video that demonstrates the issue. Ambient air temperature is 43 F in this video:

https://www.youtube.com/watch?v=FP8i8MWwWxc


Our Kubota dealer and reps have been working hard to try and figure it out but haven't had any luck. Here's what's been done so far:

1. ECU accessed and analyzed. Air intake heater replaced, no other codes.
2. engine compression test performed. Meets published specifications and there are no indications of anomalies or technical issues
3. PTO horsepower checked by calibrated dynamometer. Meets published specifications and gives no indication of anomalies or other technical issues.
4. Entire fuel system checked for cleanliness or leaks. No issues found.
5. Fuel injectors removed and tested at factory lab. No issues found.

Does anyone have any ideas or can I expect this to be normal? I have started several other tractors and none have demonstrated this. Any help would be appreciated. Thanks

 

[Tooljunkie]

Only thing i would consider is a sticking valve, or one thats a little tight. Expansion occurs during warm up and all is fine until next cold start. No way to test compression while its running.

Start tractor, bring up rpms and go feel exhaust manifold where it comes out of head. One will be cooler than the others. That is the cylinder i would check the valve settings on.
Or something is up with injection pump.

 

[D2Cat]

"Start tractor, bring up rpms and go feel exhaust manifold where it comes out of head. One will be cooler than the others. That is the cylinder i would check the valve settings on."

Or use your handy dan infrared thermometer.

 

[Steve NC]

White smoke usually comes from raw unburnt fuel passing out the exhaust completely intact. The most common causes are
1.faulty injectors
2.incorrect ignition timing (worn or damaged crankshaft key)
3.low cylinder pressure cause by worn,broken or sticky valves, sticking piston rings or cylinder glaze.

Usually when you see white smoke at start up and then it disappears as the engine warms up, the problem usually is tracked down to fouling deposits on the piston rings or a glazed cylinder.

If it was my tractor I would check the quality of the fuel and add something like seafoam motor treatment to the fuel and the engine oil to clean the rings and the injectors. Marvel mystery oil is another choice but the seafoam has worked better for me in the fuel.

Your dealer has already checked for most of the common problems but its just my opinion but im leaning toward deposits on the rings. I had a chance to try out a tractor in your series, I think it was the m135x. Amazing machine!

https://seafoamsales.com/diesel/
http://www.marvelmysteryoil.com/

 

[Tooljunkie]

I was thinking a fuel quality issue too, and a can of sea foam is a small investment to see if it helps, would take some run time for it to do its job. Its amazing stuff

 

[North Idaho Wolfman]

Our Kubota dealer and reps have been working hard to try and figure it out but haven't had any luck. Here's what's been done so far:

1. ECU accessed and analyzed. Air intake heater replaced, no other codes.
2. engine compression test performed. Meets published specifications and there are no indications of anomalies or technical issues
3. PTO horsepower checked by calibrated dynamometer. Meets published specifications and gives no indication of anomalies or other technical issues.
4. Entire fuel system checked for cleanliness or leaks. No issues found.
5. Fuel injectors removed and tested at factory lab. No issues found.

That is one complicated monster, common rail machines are always more difficult to access.
Have they checked fuel pressures?
The Infrared Thermometer is a really good idea because it will tell you if it's all cylinders or just one, if it's one I would lean towards a bad valve or valve train (week hydraulic lifter?) since they have already gone through the injectors.
If all cylinders are week, I would lean to bad / worn turbo, or some restriction in the intake (collapsed filter or hose?), or possibly a bad EGR valve?

 

[andyman]

Thanks everyone for your suggestions and ideas. I appreciate it. I will forward these to Kubota reps. Hopefully, these will yield the solution.

 

[D2Cat]

andyman, you in Missouri, or some other West Plains?

 

[andyman]

andyman, you in Missouri, or some other West Plains?

Yes, D2Cat, I'm in West Plains, Missouri.

 

[andyman]

That is one complicated monster, common rail machines are always more difficult to access.
Have they checked fuel pressures?
The Infrared Thermometer is a really good idea because it will tell you if it's all cylinders or just one, if it's one I would lean towards a bad valve or valve train (week hydraulic lifter?) since they have already gone through the injectors.
If all cylinders are week, I would lean to bad / worn turbo, or some restriction in the intake (collapsed filter or hose?), or possibly a bad EGR valve?

Thanks for your reply Wolfman. They have checked the fuel pressure, injectors and fuel. To my knowledge, they didn't check the valves, turbo or intake. They have done, as best I can tell from my non-mechanic point of view, a pretty thorough job at troubleshooting. They just haven't pinpointed the issue yet.

 

[andyman]

White smoke usually comes from raw unburnt fuel passing out the exhaust completely intact. The most common causes are
1.faulty injectors
2.incorrect ignition timing (worn or damaged crankshaft key)
3.low cylinder pressure cause by worn,broken or sticky valves, sticking piston rings or cylinder glaze.

Usually when you see white smoke at start up and then it disappears as the engine warms up, the problem usually is tracked down to fouling deposits on the piston rings or a glazed cylinder.

If it was my tractor I would check the quality of the fuel and add something like seafoam motor treatment to the fuel and the engine oil to clean the rings and the injectors. Marvel mystery oil is another choice but the seafoam has worked better for me in the fuel.

Your dealer has already checked for most of the common problems but its just my opinion but im leaning toward deposits on the rings. I had a chance to try out a tractor in your series, I think it was the m135x. Amazing machine!

https://seafoamsales.com/diesel/
http://www.marvelmysteryoil.com/

I had found a similar suggestion about the fouled piston rings or a glazed cylinder. They didn't think this was the case due to the compression of each cylinder testing well within specified limits.

What would cause a piston to foul or cylinder to glaze?

Does Seafoam void any part of the Kubota warranty?

Thanks for your input.

 

[andyman]

Only thing i would consider is a sticking valve, or one thats a little tight. Expansion occurs during warm up and all is fine until next cold start. No way to test compression while its running.

Start tractor, bring up rpms and go feel exhaust manifold where it comes out of head. One will be cooler than the others. That is the cylinder i would check the valve settings on.
Or something is up with injection pump.

Thanks for your input, I appreciate the suggestions.

 

[Tx Jim]

Only thing i would consider is a sticking valve, or one thats a little tight. Expansion occurs during warm up and all is fine until next cold start..

If engine had a sticking valve would it fail the compression test that OP stated it passed?

 

[Steve NC]

I had found a similar suggestion about the fouled piston rings or a glazed cylinder. They didn't think this was the case due to the compression of each cylinder testing well within specified limits.

What would cause a piston to foul or cylinder to glaze?

Does Seafoam void any part of the Kubota warranty?

Thanks for your input.

Usually the cause of the foul or glaze can be traced back to fuel quality. The way the engines are being made today the tolerances are so tight that there is little room for error. My company was having trouble with some of the newer Caterpillar engines a few years ago. The cause was traced back to the service man filling the new fuel filters with fuel from a can. The filter on the tank he was getting the fuel from wasn't filtering particles small enough to catch everything before it hit the injectors. Pouring fuel into the filter helps cut down on the time it takes to prime the engine but it allows some to enter the engine unfiltered. Caterpillar recommended they start putting the new filters on empty and using the priming pump the way the system was designed. After having these issues they started using seafoam to fill the filters and help clean the system at the same time. According to Seafoam's website it will not void the warranty. They also claim you cant add too much to the fuel.

 

[North Idaho Wolfman]

If engine had a sticking valve would it fail the compression test that OP stated it passed?

That would depend on if they did it warm or cold.

This engine has 4 valves per cylinder so you double the chances that it could be a valve issue!

 

[Bulldog]

Sounds like a 6.0 Ford with a stiction issue. Cold, the injectors stick and the engine will smoke and miss like crazy. It slowly clears up and will stop missing after the engine temps get all the way up to normal.

 

[Frank minarchi]

Maybe it's like my B3200. It did the same thing till we advanced the timing. And ever since 30 above or 30 below it fires up perfectly with no white smoke anymore or sputtering. Just an idea.

 

[Boutch]

Hi Andy here is a video of 2011 M100x with 750hrs, taken today temps was about 35 degrees. Added Cetane additive last week and put a couple hrs on since. And it pretty much gone now. For you guys following this tread, my was doing the same thing but not as bad. only happened between 32 and 60-65 degrees. It did not Mather if I tried to start it the next day or if it sat for 2 weeks. below 32 when the glow plugs and air pre-warmer kicks in it is fine and it is fine also at warmer temps above 65.


https://youtu.be/yVpp21X5H9Y

 

[andyman]

Thanks for the input. It is helpful. I will visit with the dealer about it.