New L5240 Starting Rough

AJNF

New member

Equipment
L5240
Jun 22, 2011
4
0
0
Colorado Springs
Hi,

I am new to OTT as well as a first time Kubota owner. I sold my JD and went orange last month and so far I am very happy. There is one issue I am concerned about and I would like some input from the members.

When I start the tractor it idles very rough and blows a lot of white smoke. I had the service tech back out to have a look at it and he said that was normal. At the same time he also noticed the coolant was low and topped it off. He said the coolant was low due to the addition of the block heater and there may have been a bubble in the system. I have owned several diesels (both tractors and trucks) and I know white smoke is never a good thing when it comes to diesels.

I took a video of the tractor starting so you can get a better idea of what I am talking about. I was about 65 degrees out and the tractor had sat all night. Here is the link http://youtu.be/W4X3dJ8QvOQ or you can click here

Thanks for your help.
 

Hook

Member

Equipment
L3240 with LA514 FEL, Box Blade, Howard Rotovator, All Purpose Plow, Sub Soiler
Jul 6, 2010
209
2
18
Jackson, Georgia
Seems that I recall some threads about new Kubotas smoking and running rough due to injector timing issues. Also are you using the glow plug before starting? The low coolant could be a hint also but I would not think so since your tractor is new.
 
Last edited:

AJNF

New member

Equipment
L5240
Jun 22, 2011
4
0
0
Colorado Springs
Hi Hook,

Thanks for the feedback.

I always wait until the glow-plug light goes out before starting. I have even tried cycling the key several time is assure the plugs are at max hot.

I will do a search on injection timing and see if I can find anything.
 

Hook

Member

Equipment
L3240 with LA514 FEL, Box Blade, Howard Rotovator, All Purpose Plow, Sub Soiler
Jul 6, 2010
209
2
18
Jackson, Georgia
I'm no expert but I also have a 40 series with no such issues. Makes me wonder what is "normal". Let us know what you find out.
 

78Vette

New member

Equipment
F2690
Mar 14, 2010
109
1
0
SW Ont. Canada
My L3240 is just a liiiiittle lumpy when i first start it, but not like yours is.
No white smoke on mine and dont recall having any when it was brand new. I have 60 hours on it now. Keep your eye on the coolent bottle.
 

AJNF

New member

Equipment
L5240
Jun 22, 2011
4
0
0
Colorado Springs
I tried the 1/2 throttle start. Still blowing a lot of white smoke and running rough but it seems to get up and running faster.

I would have to agree with kuboman, starting the engine in that manner would put added stress on a cold and unlubricated engine.

Personally, I think there is something wrong and I plan to take it back to the dealer to have it tuned by a tech.

Let me know what you think.

Here is the link to the video of a 1/2 throttle start: http://youtu.be/XBj4_PiXEVE or click here http://youtu.be/XBj4_PiXEVE
 

AJNF

New member

Equipment
L5240
Jun 22, 2011
4
0
0
Colorado Springs
Here is the reply from Kubota:

Good afternoon,
I am the Division Service Manager for Kubota based in our Fort Worth, TX
office. Your email and video have been forwarded to me for a response. I
have viewed the videos you supplied, and offer the following observations /
comments:

1. At a cold start, the initial puff of smoke appears to be black followed
by white.
2. Within 3-5 seconds this clears up and the tractor exhaust shows no
visible sign of smoke.
3. I assume there are no other concerns or symptoms such as lack of power,
or missing under load.
4. I also assume the elevation where you are located is 4000-5000 feet
above sea level. (We are at 7600 feet)
5.Your tractor is equipped with a Kubota diesel engine that is Interim
Tier-4 certified for exhaust emissions.

Considering the above, it is my opinion that the initial smoke and
"stumbling" the engine is experiencing, is consistent with the performance
of an Interim Tier-4 certified engine.

Your altitude will also have an impact during initial cold start up. But
since this is a turbocharged engine, once the engine is started, the
turbocharger is functional and altitude should not be a major factor
when operating in the field.

Thank you for purchasing Kubota products.

Dave Haggerty
Central Division Service Manager
14855 FAA Blvd. Fort Worth, TX 76155


I guess that is how is should run. Now I just have to remember to not start the tractor in the barn when my wife is milking. :eek:

Thanks for all the great feedback!
 

Wildfire

Active member

Equipment
Kubota L5740 HSTC3 and a Kubota ZG222Z, 2013 BX25D,Custom Toyota fork lift.
I have a 2008 4240 Grand L cab with 200 hours on it and a 2011 5740 Grand L cab with 2 hours and none of them have white smoke after start up. They both have the initial black smoke on start up for a few seconds but clear up after that. Get your machine checked. Something's out of whack.
 

dfixit1

Member

Equipment
L4240HSTC-3
May 17, 2019
140
15
18
United States
I know this is an old thread but my 2012 L4240HstC-3 does the same thing, lots of white smoke below 46* and stumbles for about 10 seconds. I too have taken videos and showed them to the service manager at my local kubota dealer. He says it’s normal for Intrim Tier-4 engine. Then I purchased a used front Kubota snowblower from a guy who had the same year and model tractor as mine and his didn’t smoke like mine. He had a mobile tractor mechanic remove the hydraulic hose and fittings from his HST and brackets for the sale and gave me the mechanics business card. I had called him, he worked at the kubota dealer for 12 years then went on his own. He said about half of them smoke and half don’t. He also said it’s normal. I’ve been told they only have to pass emissions when hot. My understanding is, the timing and fuel is mechanical set, unlike the newer ones with the dpmf and catalytic which are computer controlled for emissions and trims for cold start.
I sure would like to pick the engineers brain on why some smoke and some don’t? Is it timing settings, fuel injector pump settings, shims, etc? I would guess the settings are very sensitive and have a variable that causes it.
It would be great to borrow the one that doesn’t and compare it against the one that does.
I tried the recommended cold start in the manual by raising the throttle and it makes it worse. It’s just getting too much fuel on a cold start in my opinion but could be related to the timing setting too.
So I use the block heater and plug it in with a WiFi smart plug with a light in the window. Turn on with the app 1.5 hrs before using and only get a brief puff and it good. The light is my safety feature, light on, block heater is on.
 
Last edited:

Dave_eng

Well-known member
Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
4,641
642
113
Williamstown Ontario Canada
Your block heater can be a problem on certain generations of Kubota's.

Does your tractor have a GP controller which decides how long the GP's heat before the engine is ready to start?

The controller is fooled by the warm engine block and greatly shortens the time the GP's are heated.

When the engine then cranks it is inhaling very cold air and the warm block is not helping.

On the new common rail engines when a dealer installs a block heater the temp signal for the gP controller is changed from the block temp to outdoor air temp. Now the ON time of the GP's reflects what conditions the engine is trying to start under.

Please read the document I have attached. My Kubota is a 2012 M7040. Our tractors may both use the same GP controller.

Dave
 

Attachments

Last edited:

loggin

Member

Equipment
MX4700
Sep 4, 2021
45
17
8
canada
I know this is an old thread but my 2012 L4240HstC-3 does the same thing, lots of white smoke below 46* and stumbles for about 10 seconds. I too have taken videos and showed them to the service manager at my local kubota dealer. He says it’s normal for Intrim Tier-4 engine. Then I purchased a used front Kubota snowblower from a guy who had the same year and model tractor as mine and his didn’t smoke like mine. He had a mobile tractor mechanic remove the hydraulic hose and fittings from his HST and brackets for the sale and gave me the mechanics business card. I had called him, he worked at the kubota dealer for 12 years then went on his own. He said about half of them smoke and half don’t. He also said it’s normal. I’ve been told they only have to pass emissions when hot. My understanding is, the timing and fuel is mechanical set, unlike the newer ones with the dpmf and catalytic which are computer controlled for emissions and trims for cold start.
I sure would like to pick the engineers brain on why some smoke and some don’t? Is it timing settings, fuel injector pump settings, shims, etc? I would guess the settings are very sensitive and have a variable that causes it.
It would be great to borrow the one that doesn’t and compare it against the one that does.
I tried the recommended cold start in the manual by raising the throttle and it makes it worse. It’s just getting too much fuel on a cold start in my opinion but could be related to the timing setting too.
So I use the block heater and plug it in with a WiFi smart plug with a light in the window. Turn on with the app 1.5 hrs before using and only get a brief puff and it good. The light is my safety feature, light on, block heater is on.
I realize this may be a long shot but have you checked to make sure the bleed screw is hand tight? It is typically located at the injector pump. Mine had worked itself a little loose over time and seemed to make the engine a little harder to start.

Just a suggestion.
 

dfixit1

Member

Equipment
L4240HSTC-3
May 17, 2019
140
15
18
United States
Your block heater can be a problem on certain generations of Kubota's.

Does your tractor have a GP controller which decides how long the GP's heat before the engine is ready to start?

The controller is fooled by the warm engine block and greatly shortens the time the GP's are heated.

When the engine then cranks it is inhaling very cold air and the warm block is not helping.

On the new common rail engines when a dealer installs a block heater the temp signal for the gP controller is changed from the block temp to outdoor air temp. Now the ON time of the GP's reflects what conditions the engine is trying to start under.

Please read the document I have attached. My Kubota is a 2012 M7040. Our tractors may both use the same GP controller.

Dave
Hi Dave, mine is a HST not a Shuttle Shift.
Did you modify yours for air temperature?

”When the engine then cranks it is inhaling very cold air and the warm block is not helping.” It helps mine, that’s why I use it.

When I use the block heater my glow plug time is shortened and it starts correctly. Prior to the block heater install and glow plugs replacement with the new part number I would double or triple cycle them with the key. It helped some but I didn’t want to damage them by overheating them. I wouldn’t say it’s fooled by the warm coolant, it correctly shortens the glow plug time with coolant temperature. The issue is over fueling because of the I-tier 4 Not length of time the relay stays on. I also updated the relay with the correct spade terminal size as this was also an issue. Regards
 

dfixit1

Member

Equipment
L4240HSTC-3
May 17, 2019
140
15
18
United States
I realize this may be a long shot but have you checked to make sure the bleed screw is hand tight? It is typically located at the injector pump. Mine had worked itself a little loose over time and seemed to make the engine a little harder to start.

Just a suggestion.
Mine starts promptly. Thanks
 

Dave_eng

Well-known member
Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
4,641
642
113
Williamstown Ontario Canada
Hi Dave, mine is a HST not a Shuttle Shift.
Did you modify yours for air temperature?

”When the engine then cranks it is inhaling very cold air and the warm block is not helping.” It helps mine, that’s why I use it.

When I use the block heater my glow plug time is shortened and it starts correctly. Prior to the block heater install and glow plugs replacement with the new part number I would double or triple cycle them with the key. It helped some but I didn’t want to damage them by overheating them. I wouldn’t say it’s fooled by the warm coolant, it correctly shortens the glow plug time with coolant temperature. The issue is over fueling because of the I-tier 4 Not length of time the relay stays on. I also updated the relay with the correct spade terminal size as this was also an issue. Regards
I did not make any changes to where temp signal comes from.

Seeing the mechanic start a long line of various machines easily in very cold weather was what prompted me to find out how.

My engine does not even turn over before firing. This is the 9th year of doing this.

On mine you cannot cause a second GP cycle.

Dave
 

dfixit1

Member

Equipment
L4240HSTC-3
May 17, 2019
140
15
18
United States
Here is the reply from Kubota:

Good afternoon,
I am the Division Service Manager for Kubota based in our Fort Worth, TX
office. Your email and video have been forwarded to me for a response. I
have viewed the videos you supplied, and offer the following observations /
comments:

1. At a cold start, the initial puff of smoke appears to be black followed
by white.
2. Within 3-5 seconds this clears up and the tractor exhaust shows no
visible sign of smoke.
3. I assume there are no other concerns or symptoms such as lack of power,
or missing under load.
4. I also assume the elevation where you are located is 4000-5000 feet
above sea level. (We are at 7600 feet)
5.Your tractor is equipped with a Kubota diesel engine that is Interim
Tier-4 certified for exhaust emissions.

Considering the above, it is my opinion that the initial smoke and
"stumbling" the engine is experiencing, is consistent with the performance
of an Interim Tier-4 certified engine.

Your altitude will also have an impact during initial cold start up. But
since this is a turbocharged engine, once the engine is started, the
turbocharger is functional and altitude should not be a major factor
when operating in the field.

Thank you for purchasing Kubota products.

Dave Haggerty
Central Division Service Manager
14855 FAA Blvd. Fort Worth, TX 76155


I guess that is how is should run. Now I just have to remember to not start the tractor in the barn when my wife is milking. :eek:

Thanks for all the great feedback!
I’d sure like to ask this Central Division Service Manager why some do it and some don’t? You’d think there’s an internal memo, technical service bulletin or something about it other than the blanket answer that it’s normal.