Kubota L245DT exhaust oil

[drmaster]

My L245DT has oil or unburned deisel running down the exhaust stack. Does anyone know what might be causing this and how to prevent it? I was using the backhoe for 2 - 3 hours with the engine running at around 1700 rpm when this first occured. Thanks

 

[KJM]

I'm not a diesel mechanic, so this might be off beam a fair way. I'd guess exhaust valve seals.

You didn't say if the engine was running OK? If it is OK, then the oil must be coming into the system after the combustion chamber - otherwise the oil would burn (and you'd have an engine not-controlled-by-the-throttle with large amounts of blue oil smoke).

Now, why the valve stem seal is suddenly leaking is another question - do you have a lot of blow-by? Could just be that there is excess pressure in the engine due to leaky rings and with the smaller Kubotas I've see the rocker box get LOTS of oil pumped into it and the excess oil makes its way out the breather pipe and into the valve seals.

Just my $0.02.

/Kevin

 

[DieselPower]

Not familiar with the engine in your tractor but here are some starting points.

First, you need to figure out if it is oil or fuel.

If it's oil and it is a turbo charged engine DO NOT RUN IT ANYMORE! If it is the seal within the turbo you could be pumping engine oil from your turbo into the engine. A running diesel engine can "run away" when the turbo oil seal goes. Even if you shut the engine off it will continue to run on the engine oil and the RPM's will continue to increase until it blow's up. Seen it happen more times than I can count on my fingers. To check for this, remove the turbo clean air side/preasure out line and see if there is any oil in it. If there is even a trace amount of oil in the preasurized air side the seal is gone. Get the turbo rebuilt.

Next it could be bad valve seal's but usually this will not be enough oil to be noticed running out of the exhause.

What color smoke is coming out of the exhaust? White or blue? Blueish black smoke is probably engine oil. White smoke is fuel.

If it's fuel you may have a injector that is bad and is pissing a stream of raw fuel into one of your cylinders. Check where your exhaust manifold mounts to the engine block. Fuel being very thin will usually leak out around the bad injectors cylinder. If there is something seaping out around one of the exhaust ports suspect a bad injector.

There are numerous other things that could cause a over fueling problem but not being familiar with your exact engine it's hard to comment on your exact system.

 

[Soundguy]

One other option.. could be just simple old diesel slobber.

If it is just a little bit of slobber.. probaby not much to worry about.

Do check on the other info posted.. EG turbo seals.. ad valves.

Soundguy

 

[drmaster]

Thanks for the information. I'll try and answer some of the questions to see if it will narrow the scope of my investigation. The engine is a Kubota DH1101-A, 3 cylinder, vertical, water cooled 4 cycle engine, without a turbo, rated at 25 horse power. The engine appears to run as well as it ever has with little visible smoke of any color. There is black oil or diesel leaking between where the exhaust manifold attaches to the engine block on only the front cylinder. Additional oil, or diesel, can be seen leaking through small holes where the 3 sections of the manifold come together going up the stack.

Any additional advice would be greatly appreciated!

 

[KJM]

OK, so the thing is basically going just fine - which probably means there is not too much wrong.

Before going the whole hog on the valve seals, check the rocker box (top cover, whatever you guys call it over there!). My B7100 had a minor leak when I got it. The oil basically spread backwards on the injector side of the motor. It looked for all the world like serious trouble, but when I cleaned it up and did the tappet adjustment; the problem was fixed. Just a thin smear of Silicone turned out to be a total cure. I hope this is all that is wrong with it!

I'd bet on some kind of external leak like this, given that it is working fine and the smoke is normal.

Cheers
/Kevin

 

[KICK]

LET IT RIDE, UNLESS IT HAS SOME OTHER ISSUES LIKE IT MISFIRES ETC. OR YOU HAVE TO AD OIL EVERY TIME YOU RUN IT.

ONE OTHER IDEA, EXTENDED LIGHT LOAD OPERATION AT LOWER THAN NORMAL COLANT TEMPS CAN CAUSE SOME OIL CARRYOVER.

 

[Soundguy]

Thanks for the information. I'll try and answer some of the questions to see if it will narrow the scope of my investigation. The engine is a Kubota DH1101-A, 3 cylinder, vertical, water cooled 4 cycle engine, without a turbo, rated at 25 horse power. The engine appears to run as well as it ever has with little visible smoke of any color. There is black oil or diesel leaking between where the exhaust manifold attaches to the engine block on only the front cylinder. Additional oil, or diesel, can be seen leaking through small holes where the 3 sections of the manifold come together going up the stack.

Any additional advice would be greatly appreciated!

Sounds more like slobber now...

Sometimes water gets downt he muffler.. that and soot.. and a little blowby and/or from extended idling.. etc.. will produce slobber.

If you feel like it.. remove the manifold.. see if it is chock full of gooey gunk.. clean it.. and slap it back on with a new gasket.. see where that gets you.

Soundguy

 

[Birdman253]

Also might be as simple as crankcase breather plugged. Find the breather, and make sure it is not plugged. IIRC, some Kubota's vented with a pipe that was wide open at the end, and a favorite spot for mud daubers.

 

[dfkrug]

If it's oil and it is a turbo charged engine DO NOT RUN IT ANYMORE! If it is the seal within the turbo you could be pumping engine oil from your turbo into the engine. A running diesel engine can "run away" when the turbo oil seal goes. Even if you shut the engine off it will continue to run on the engine oil and the RPM's will continue to increase until it blow's up. Seen it happen more times than I can count on my fingers. To check for this, remove the turbo clean air side/preasure out line and see if there is any oil in it. If there is even a trace amount of oil in the preasurized air side the seal is gone. Get the turbo rebuilt.

.

Hey, Diesel, is this really common? It seems to me there are thousands
of big trucks with turbos and 500,000+ miles between overhauls. A
sudden catastrophic seal failure in the turbo seems unlikely. Clearly
there is no way to shut off the engine if this happens, as you say.
More likely the seal starts leaking a bit and is noticed by excessive
blue smoke and/or low engine oil.

I am still waiting for a DIY guy to add a turbo to his tractor and post
his experience on TBN. A small IHI unit on a 1.5-liter 3-cyl at 7psi
boost and no intercooler looks like a fairly easy proposition.