Kubota L3400 Blue Smoke

[Robert walker]

I have a 2004 Kubota L3400DT that started smoking when I start it and when I accelerate. If I push the throttle it will puff out blue smoke, I know it’s burning oil, I can smell it. i bought this tractor new, it has about 900 hours. Have always changed the oil at 200 hours. Could I have valve stem seals leaking or do y’all think I need to put new rings in it? Another issue that started not too long ago is that it will start right up cold, big puff of blue smoke, but once it warms up if I turn it off it’s hard to get it to turn over and fire back up. I know it’s a lot but I have to tear it down and get it fixed.

 

[dodge man]

I’m not a lot of help but I’d figure out what’s wrong before tearing it down, it might be something minor. Do these have a PCV valve on them? I’d start there and check that. 900 hours is nothing on a diesel engine unless it was overheated or neglected.

 

[Tomtint]

Start with the easy stuff...Like checking the air filter.

 

[Thomas]

Are you using fresh diesel?
What RPM's do you run?

 

[Jerry/MT]

I have a 2004 Kubota L3400DT that started smoking when I start it and when I accelerate. If I push the throttle it will puff out blue smoke, I know it’s burning oil, I can smell it. i bought this tractor new, it has about 900 hours. Have always changed the oil at 200 hours. Could I have valve stem seals leaking or do y’all think I need to put new rings in it? Another issue that started not too long ago is that it will start right up cold, big puff of blue smoke, but once it warms up if I turn it off it’s hard to get it to turn over and fire back up. I know it’s a lot but I have to tear it down and get it fixed.

How hard do you work it? Your oil control rings might be loaded up with carbon from not getting the engine up to temperature long enough. Are you using a Diesel rated lube oil in the engine?

At 900 hrs, I doubt it's a compression problem but since it's 19 years old and only has 900 hours on it, me thinks it hasn't been worked hard. Before you start tearing it a part, work the snot out of it for about 10-20 hours and see if you get some improvement.
As far as hard starting when hot, make sure that the battery and the chasis ground connection terminals are "bright and tight". How old is your battery? Have it tested.

 

[Robert walker]

How hard do you work it? Your oil control rings might be loaded up with carbon from not getting the engine up to temperature long enough. Are you using a Diesel rated lube oil in the engine?

At 900 hrs, I doubt it's a compression problem but since it's 19 years old and only has 900 hours on it, me thinks it hasn't been worked hard. Before you start tearing it a part, work the snot out of it for about 10-20 hours and see if you get some improvement.
As far as hard starting when hot, make sure that the battery and the chasis ground connection terminals are "bright and tight". How old is your battery? Have it tested.

I mow pastures with it in the fall, gonna start early this year probably. I don’t go fast but I pull a 6’ mower with it. i have a couple spots that I’m going to mow in 3 weeks, I sprayed them today, trying to kill cockaburs. While I have abused it, I do feel like I have worked it hard since I bought it. I will give it a try. I do plan on changing all fluids before I start mowing.
Seems like the battery isn’t but 3 years old but I have a new one I bought for something else and ended up not using it. I’m gonna charge it, and swap it out to see if that will take care of that problem. Thanks

 

[Jerry/MT]

I mow pastures with it in the fall, gonna start early this year probably. I don’t go fast but I pull a 6’ mower with it. i have a couple spots that I’m going to mow in 3 weeks, I sprayed them today, trying to kill cockaburs. While I have abused it, I do feel like I have worked it hard since I bought it. I will give it a try. I do plan on changing all fluids before I start mowing.
Seems like the battery isn’t but 3 years old but I have a new one I bought for something else and ended up not using it. I’m gonna charge it, and swap it out to see if that will take care of that problem. Thanks

How tall is the grass and how long of time are you operating the tractor when you mow? Does your coolant temperature indication move up a bit when you are mowing due to increased load? ( not because the radiator is clogged with chaff).

 

[Robert walker]

How tall is the grass and how long of time are you operating the tractor when you mow? Does your coolant temperature indication move up a bit when you are mowing due to increased load? ( not because the radiator is clogged with chaff).

Yes, it will go up some. Right not it’s mostly weeds and about 2’

 

[Robert walker]

Start with the easy stuff...Like checking the air filter.

I replaced the air filter and that helped a lot. It had about 200 hours on It give or take 50. i Took the negative battery cable off and cleaned both ends, went to start it and it went to turn over and quit. I think the hard starting part of my original post may have made the starter relay eat the dirt. Gonna trouble shoot it this morning. It’s been too hot in east Texas to do much during the day.

 

[workinonit]

Personally I don't think running a bush hog is going to load it to the point that Jerry is referring to. I can pull a 21 foot finish mower and don't see much increase in load at all. probably 10%. Once you spin up a bush hog it doesn't require much to turn it unless you get it in some really thick stuff.

 

[Robert walker]

Personally I don't think running a bush hog is going to load it to the point that Jerry is referring to. I can pull a 21 foot finish mower and don't see much increase in load at all. probably 10%. Once you spin up a bush hog it doesn't require much to turn it unless you get it in some really thick stuff.

In august i always disk up about 10 acres and plant rye for the winter. I will be putting through the test eventually.

 

[workinonit]

If you want to load it up put a chisel plow behind it.

 

[old and tired]

How many hours on the tractor?

 

[Robert walker]

How many hours on the tractor?

About 900

 

[Robert walker]

Well, got one thing corrected. Took starter off and it would not do anything when I hooked up on bench. Decided if I was going to have to buy a starter I may as well open it up and look. One of the brushes was stuck off the motor commutator. I took it out and cleaned it with wd-40, couldn’t find my electrical cleaning spray, put it together and it worked as it should. I put it back on the tractor and this seems to have done the trick.

As I said yesterday I changed the air filter out and it seems to have cut out the blue smoke. im In no way trying to educate y’all, your knowledge is so valuable to this forum. There is a hose that runs from the valve cover to the air intake, engine side of the air filter. I wonder if the air filter was clogged enough to make it suck oil through this hose. That’s my best educated guess. I’m gonna mow some next week and when done change all fluids, see if that will clear everything up. Thanks for all y’all’s help.

 

[Tomtint]

900 hours is not much for that tractor. I was on my L3700SU yesterday to help load a flat skid steer tire into the bed of a dump truck and looked at my hour meter for the first time ..in a long time.. Im at 350 hours. .. Not much IMO..I primarily use it to drag a LPGS on my road and pick up brush to bring to the burn pile in the winter.

 

[stephanadams]

I have a 2004 Kubota L3400DT that started smoking when I start it and when I accelerate. If I push the throttle it will puff out blue smoke, I know it’s burning oil, I can smell it. i bought this tractor new, it has about 900 hours. Have always changed the oil at 200 hours. Could I have valve stem seals leaking or do y’all think I need to put new rings in it? Another issue that started not too long ago is that it will start right up cold, big puff of blue smoke, but once it warms up if I turn it off it’s hard to get it to turn over and fire back up. I know it’s a lot but I have to tear it down and get it fixed.Speed Test

Do these have a PCV valve on them? I’d start there and check that. 900 hours is nothing on a diesel engine unless it was overheated or neglected.

 

[old and tired]

...One of the brushes was stuck off the motor commutator. I took it out and cleaned it...

I wonder if the air filter was clogged enough to make it suck oil through this hose... Thanks for all y’all’s help.

That's all good information to know... and Thank you for letting us know the out come!!!