2010 7040 wet stacking? You tell me.

[roygage]

Interesting story thought I would share.

Bought a used 7040 off Craig's list this past December, 1200 hours, 100 miles from home. What clinched the deal was the fellow was picking up his new skid loader the next day and beings as he was driving right past my place he would delver for free.

Next morning it shows up, he parks it and I give him his check. Fifteen minutes later I go out to start it and the battery is stone dead. Well no use fighting it, get a new battery and all is right in the world.

Few days later some heavy snow so Grandson and I go out to move snow, put a couple hours on the tractor doing some rentals and my business parking lot. It is only when I am driving it back to the shop I note some oil/soot/fuel/ take your pick, leaking from the stack.

The stack outlet looks wet, there is dripping from the joint were the header pipe hooks to the muffler. I get to the shop and pop the hood. Dang but the turbo is all slobbered up and covered in oil or fuel.

I cleaned everything up as good as I could, could not see any sign of blow-by, pulled the crankcase vent line that runs to the air intake hose just before the turbo and hooked a hose to it venting it into clean gallon jug then went for a one hour drive including some wide open down the road.

At the end of my drive there was not a trace of oil in the jug and it appeared my stack was cleaning up.

I am a automotive tech but not a diesel expert, I was puzzled by what could have happened to cause the buildup. Was my turbo leaking oil?

Made a call to an old friend who is a tractor mechanic in good standing, explained my situation. Larry's response was simply that I was wet stacking. the tractor was not being worked hard enough to bring the engine up to good temperature and the rings were letting oil by. He recommended bringing it out and hooking to his dyno and pulling it hard for an hour.

Now I am a little bummed because the type of work I had done when I had the trouble is the type of work I do. I don't pull a three bottom plow we just use it for odds and ends, putting up rafters ect. some snow removal, maybe unload an engine or two.

Then I came up with a theory I think, and hope is right. I had wondered how he had got the tractor started to run it off the trailer the day he dropped it off. Why would it start after a 100 mile trailer ride but not after it sat in the lot for 15 minutes?

What if the fellow knew the battery was weak, had the charger on it to get it started then once loaded he simply left it run? The day he delivered it the Interstate was single lane, light snow and about 0 degrees. Easy to imagine how cool the tractor was running at an idle facing into the wind and with the road conditions it would have been a 2 to 2.5 hour trip.

Now the turbo, muffler and stack are all loaded up and during my initial workout with it it was not wet stacking but cleaning itself up, generating some heat and spitting out what was already inside the exhaust system.

I called the seller and he denied having it running on the way up and was also adamant about the battery not giving him any previous trouble. He sounded sincere but I have my doubts, having it running in the cold and causing the problem just makes too much sense.

I put fresh oil in the tractor and it has been good since although until now I have used it very little since I continued to use a 5040 I had until it sold this week.

Now we find out what we got. (-:

Anyone have a similar experience?

 

[CaveCreekRay]

Your logic sounds impeccable.

It gunked up on the way out and now you are just burning out the "liquid spooge" (TECHNICAL TERM -WARNING!) built up from the cool idle on the ride out.

Find some job you can run it at high power for an hour of more and burn it out. Give it to the wife to run a few errands on. Half hour each way to the store and back at 2600 rpm in high range will cook out the goop.

Sounds like that machine is in good hands now.

Ray

 

[Diydave]

Does the stack have a flapper on top to keep rain out? If it has a bend, does it face forward or backward?

 

[D2Cat]

Your friend Larry, is probably right on. A diesel engine needs to WORK, not moving around at idle rpm. Many think the idle is saving the engine and fuel.

Search "slobber", "wet stacking" on this forum and you'll find some discussion of it.

Use your tractor, don't baby it. If you're wanting to go slow, slow the gears, not the engine.

 

[roygage]

Does the stack have a flapper on top to keep rain out? If it has a bend, does it face forward or backward?

Faces forward

 

[GWD]

Another option is to run the tractor a gear or two lower. Then do the work at the same pace as usual.

The increased RPM will work the engine and perhaps eliminate the issue. Running between 2500 RPM and 2800 RPM should do the trick. It will sound like the engine is screaming so go as high as your sensibilities will allow.

The coolant temperature gauge should go about halfway to hot. That would be pointing to 3 o'clock.

I have the same tractor but live in a much warmer climate so have not experienced the same problem. Doing a lot of ground engaging tasks also loads the tractor quite a bit and heats it up nicely.

The battery matter is unusual. Tractor batteries have a long life in my experiences.

 

[Bulldog]

I don't see why a tractor would be different than heavy equipment. Anything with a turbo should have the stack duct taped or have a turbo saver hung over the stack while it's in transport.
Wonder if the guy didn't cover it and maybe either ran in some rain or wash it off and sprayed water in the exhaust.

 

[Diydave]

if it was running, snow should not have been able to get into it. I agree, with a cover for the stack, during trailering. A rag down the stack, or a can on top will prevent the turbo from spooling during transit.

 

[85Hokie]

Your friend Larry, is probably right on. A diesel engine needs to WORK, not moving around at idle rpm. Many think the idle is saving the engine and fuel.

Use your tractor, don't baby it. If you're wanting to go slow, slow the gears, not the engine.

Best words I have heard today !!! I could not have said it better! Soooo many people feel that they need to baby it, putt around and most bog down the tractor and wonder why is cannot do as they wish. And no I am not saying run it at WOT - but then again, there is a reason for WOT on a diesel .......

I find that on my BX - even a 2200-2500 rpms that I am not getting where I should be if that makes sense, whether using the bucket or digging with the hoe - it ALL works , but not where the machine makes any "power" - but at 2800 rpms and even at 3400 rpms (WOT) there is a serious improvement in power and speed. But even though I hear it sing at 3400 - I too back off of it - scared that I am running it too hard!!

 

[Stubbyie]

Can't add much to the turbo discussion as never had a problem with one that demanded attention thus no learning--except listening here.

But the battery perhaps a thought:

Most likely for it's entire life that machine had trundled around a farm place at not much more than a fast walk. Suddenly it gets loaded and bumped and shaken for couple hours at 70-mph aboard a trailer.

My suspicion is that the battery had accumulated a sulphate layer on the plates due to age and lack of maintenance-level charging. When that layer of crud shook loose due to trailering it effectively shorted out the battery internals. Result? A dead battery that might otherwise have continued working.

I've had this same thing occur a couple times over a somewhat misspent and happenstance life and it was always the oldest batteries and things that didn't get moved much at highway speed.

May I offer an analogy, in the form of a short recount of something else that's happened to me? Transporting a gasoline engine, small, like in small riding mower. Carburated, not injected. Bouncing down the road on a trailer the float comes off seat and, being lower than the fuel tank, promptly siphons and floods the crankcase with fuel. Get to destination and cranked it and got huge smoke cloud out exhaust. Then checked the oil--again, as before transport--and found gassy oil almost overtopping the filler tube. What th'? Figured it out, changed oil, and proceeded. But now all our small engines have fuel cutoff valves installed and are run dry (in the carb) before transport.

So, think of your battery and its sulphate as a carb flooding the crankcase when violently shaken, not stirred.

See, you knew this story would go somewhere.

Please post back your continuing experiences so we may all learn.

"Bond, James Bond."

 

[sheepfarmer]

I am wondering what the long term impact on the engine of the new "auto throttle" feature will be? Or if the computer controlled fuel injection will change this effect and minimize diesel slobbers etc?

In auto throttle the rpm and ground speed go up together when you step on the hst pedal. So the rpm is varying constantly, and the max speed is determined by the gear. You can set a minimum rpm for the hst with the hand throttle, but the manual says to set it at idle. The max rpm when the pedal is fully depressed is at the top of the gauge. I tend to choose the turtle mode, and gear M, so that it is at max rpm when I am going as fast as it is safe to go running out to the back pasture with a load of manure, but it drops down at the beginning and end of the run automatically. So in effect it is not running at max much of the time.

 

[Dave_eng]

Some people think higher rpm's will prevent diesel slobber but actually it is high cylinder pressures which drive the rings against the cylinder walls maintaining a good seal. Running at high rpm's with no real load will be almost as bad as idling around.

Did I read that you had a friend who offered to put your tractor on a dyno for a couple of hours. Best thing in the world for it. Ask a farmer to plow a field with it. I find snow blowing works my M7040 very hard.

There have been posts about some models of kubotas experiencing a run-a-way condition when the crankcase vent system would freeze up and crankcase oil would be forced up the turbo drain line and the tractor would rev to destruction running on crankcase oil.

I think some year or model of M7040 were involved so checking your tractors details with a good dealer would be wise.

If the run-a-way condition ever happens to you, a CO2 fire extinguisher directed at the air intake will cut off the oxygen and stop the engine. Some owners who have had this happen have a piece of wood made to close off the intake. Never use your hand as the skin can be sucked off.

The run-a-way phenomenon would sometimes happen to gasoline delivery tankers when dumping a load at a service station. The engine would start inhaling the gas fumes and take off. Specialty tractors for fuel delivery at one time had a manual air shut off to kill the engine.

Work your machine hard and I think you will find you have a tough durable tractor. Give it the hard work it deserves!

Dave M7040

 

[roygage]

Some people think higher rpm's will prevent diesel slobber but actually it is high cylinder pressures which drive the rings against the cylinder walls maintaining a good seal. Running at high rpm's with no real load will be almost as bad as idling around.

Did I read that you had a friend who offered to put your tractor on a dyno for a couple of hours. Best thing in the world for it. Ask a farmer to plow a field with it. I find snow blowing works my M7040 very hard.

There have been posts about some models of kubotas experiencing a run-a-way condition when the crankcase vent system would freeze up and crankcase oil would be forced up the turbo drain line and the tractor would rev to destruction running on crankcase oil.

I think some year or model of M7040 were involved so checking your tractors details with a good dealer would be wise.

If the run-a-way condition ever happens to you, a CO2 fire extinguisher directed at the air intake will cut off the oxygen and stop the engine. Some owners who have had this happen have a piece of wood made to close off the intake. Never use your hand as the skin can be sucked off.

The run-a-way phenomenon would sometimes happen to gasoline delivery tankers when dumping a load at a service station. The engine would start inhaling the gas fumes and take off. Specialty tractors for fuel delivery at one time had a manual air shut off to kill the engine.

Work your machine hard and I think you will find you have a tough durable tractor. Give it the hard work it deserves!

Dave M7040

Good advice Dave. Friend grinds feed every week also thought if need be that would give it a good workout. I understand the point you make about cylinder pressure, without a load it is not going to be very high.

Well, I say that then have to remember I don't know much about diesels and there is no throttle plate. Working on gas motors all the time I tend to fall back on what I know about them.


Some have brought up the battery problem. The hardest thing we see on batteries is simply not being used enough. people in assisted living who only use there car once or twice a week and never leave town often have to replace the battery every couple years.

Ditto for snowmobiles, motorcycles or anything else that is under-used. Years ago I took a course on battery's put together by Honda. They stated that sitting on the shelf a battery loses 1% of it's charge a day.

Once the battery's state of charge drops under 50% it starts to sulfate and it is all downhill. Back then there was no parasitic draw to speak of, now with all the computers and modules a fifty milli amp draw is considered normal and some vehicles it might be as high as 90 or 100 mA. I always envision a mA as one amp cut into 1000 pieces. I.E 250 mA would be 1/4 of an amp, or, a glove box light.
.

I am hoping that my wet stacking was simply due to that long idle on the ride over to my place and my normal usage will keep it cleaned up. I will be sure to report my results.