I have a kubota g1900 diesel lawnmower that has recently been smoking under the hood after several minutes. I changed the air filter and used an air compressor to clean the radiator but it still does it. Both of them were very dirty. I have not changed the oil since about 2 years ago but just drained it today. I did notice before I drained it that the oil seemed too much when I pulled the dip stick out. I'm not sure if it's overheating or just smoking. I already put in ethylene glycol green 50/50 in the radiator up to the cap. Any suggestions as to what's causing this would be appreciated.
White smoke after a few min
- Thread starter Lzybmbjj30
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Re: White smoke starts to we'll up under engine after running for a few minutes
Up to the cap with coolant will push out until its about 1" from the top. It needs the air space to expand. Would also look for the crankcase vent tube and see if that is where smoke is coming from. High oil level is one of three things, diesel fuel (injector pump) hydraulic oil (hydraulic pump) or coolant (head gasket)
If there was no coolant in oil when drained, thats better -maybe.
Check hydraulic oil level, unless hydraulic pump is not mounted to engine then ignore it
Seal on injection pump could be leaking/dumping fuel into engine. Also mechanical fuel pump (if equipped) could be leaking fuel into crankcase.
White smoke have a distinct odour?
Up to the cap with coolant will push out until its about 1" from the top. It needs the air space to expand. Would also look for the crankcase vent tube and see if that is where smoke is coming from. High oil level is one of three things, diesel fuel (injector pump) hydraulic oil (hydraulic pump) or coolant (head gasket)
If there was no coolant in oil when drained, thats better -maybe.
Check hydraulic oil level, unless hydraulic pump is not mounted to engine then ignore it
Seal on injection pump could be leaking/dumping fuel into engine. Also mechanical fuel pump (if equipped) could be leaking fuel into crankcase.
White smoke have a distinct odour?
Re: White smoke starts to we'll up under engine after running for a few minutes
I replaced the valve cover gasket but that wasn't the issue. Is it possible that the coolant is burning. The smoke just has a burnt smell. I can run the mower about 15 minutes or so before it starts.
I replaced the valve cover gasket but that wasn't the issue. Is it possible that the coolant is burning. The smoke just has a burnt smell. I can run the mower about 15 minutes or so before it starts.
Re: White smoke starts to we'll up under engine after running for a few minutes
See if you can run engine with hood open see exactly where the smoke is coming from, these guys can help you.
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See if you can run engine with hood open see exactly where the smoke is coming from, these guys can help you.
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Re: White smoke starts to we'll up under engine after running for a few minutes
When it starts I look under the hood and it's almost like it steams up fro the very bottom of the engine.
When it starts I look under the hood and it's almost like it steams up fro the very bottom of the engine.
North Idaho Wolfman
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Re: White smoke starts to we'll up under engine after running for a few minutes
If the level in the radiator is going down, your most likely cause is a blown head gasket or a cracked head.
If the level in the radiator is going down, your most likely cause is a blown head gasket or a cracked head.
White smoke starts to we'll up under engine after running for a few minutes
Any smoke from the exhaust? I am no mechanic but If oil level was high and rad was low and smoke is coming from vent tube or bottom en of engineand not exhaust wouldn't that indicate a cracked block.
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Any smoke from the exhaust? I am no mechanic but If oil level was high and rad was low and smoke is coming from vent tube or bottom en of engineand not exhaust wouldn't that indicate a cracked block.
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Re: White smoke starts to we'll up under engine after running for a few minutes
There is no smoking from the exhaust. It's just after about 15 minutes running white smoke steams off the entire engine. I first thought it was overheating but I guess not.
There is no smoking from the exhaust. It's just after about 15 minutes running white smoke steams off the entire engine. I first thought it was overheating but I guess not.
Re: White smoke starts to we'll up under engine after running for a few minutes
If the gasket is blown is it possible to drain the radiator and pour sealer in to fix the issue?
If the gasket is blown is it possible to drain the radiator and pour sealer in to fix the issue?
North Idaho Wolfman
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Re: White smoke starts to we'll up under engine after running for a few minutes
Kubota diesels are high compression engines and it's pretty hard for any sealer to overcome that.
Not really a good choice, and most of the time it will fail to work.
Kubota diesels are high compression engines and it's pretty hard for any sealer to overcome that.
North Idaho Wolfman
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Re: White smoke starts to we'll up under engine after running for a few minutes
A cracked block on a Kubota is extremely rare, and if it blows the head gasket it will cause coolant to be heated and forced into the oil returns in the head and block causing it to blow steam / white smoke out the breather.
OBKubota,
A cracked block on a Kubota is extremely rare, and if it blows the head gasket it will cause coolant to be heated and forced into the oil returns in the head and block causing it to blow steam / white smoke out the breather.
Re: White smoke starts to we'll up under engine after running for a few minutes
How do I get to the broken head and replace it? Does anyone have a diagram of similar engines or a good tutorial link?
How do I get to the broken head and replace it? Does anyone have a diagram of similar engines or a good tutorial link?
White smoke starts to we'll up under engine after running for a few minutes
Thanks for explanation Wolfman it just seemed strange to me nothing coming from exhaust. Good Luck on the rest of your journey Lzybmbjj30. Like I stated before these guys know there kubotas.
On a side note if I may without starting a new thread, My kubota manual says to change coolant every year Opps it been 2 years now and only 200hrs. Isn't yearly an overkill?
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Thanks for explanation Wolfman it just seemed strange to me nothing coming from exhaust. Good Luck on the rest of your journey Lzybmbjj30. Like I stated before these guys know there kubotas.
On a side note if I may without starting a new thread, My kubota manual says to change coolant every year Opps it been 2 years now and only 200hrs. Isn't yearly an overkill?
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North Idaho Wolfman
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Re: White smoke starts to we'll up under engine after running for a few minutes
I test mine every year but only replace it if lost, contaminated, or tests poorly.
Yes I think it's overkill.
I test mine every year but only replace it if lost, contaminated, or tests poorly.
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ehenry
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Re: White smoke starts to we'll up under engine after running for a few minutes
Its a D722 engine in that mower isn't it? I have the same engine in a B7300 and it did something similar once while mowing and all the steam I saw was coming from the "I'm Running Hot" whistle. Mine broke a fan belt to cause my problem. Have you checked to make sure the fan belt is still there and tight? There should also be a screen in front of the radiator make sure its clean. I'm not sure if there is a thermostat it that machine or not. If there is, is it stuck shut?
Its a D722 engine in that mower isn't it? I have the same engine in a B7300 and it did something similar once while mowing and all the steam I saw was coming from the "I'm Running Hot" whistle. Mine broke a fan belt to cause my problem. Have you checked to make sure the fan belt is still there and tight? There should also be a screen in front of the radiator make sure its clean. I'm not sure if there is a thermostat it that machine or not. If there is, is it stuck shut?
Re: White smoke starts to we'll up under engine after running for a few minutes
I spoke to a neighbor that used to work on mowers and explained the issue to him. He said it sounded like a pulley with a locked up bearing grinding the belt when the pto is engaged or even a bad pto lever.
One more thing I forgot to mention is that the brake stays depressed. Normally you depress the brake and it goes back to normal when you take your foot off for. There's a little lever next to the brake that you can engage while it's depressed that will hold it in place.
I spoke to a neighbor that used to work on mowers and explained the issue to him. He said it sounded like a pulley with a locked up bearing grinding the belt when the pto is engaged or even a bad pto lever.
One more thing I forgot to mention is that the brake stays depressed. Normally you depress the brake and it goes back to normal when you take your foot off for. There's a little lever next to the brake that you can engage while it's depressed that will hold it in place.
Re: White smoke starts to we'll up under engine after running for a few minutes
"One more thing I forgot to mention is that the brake stays depressed. Normally you depress the brake and it goes back to normal when you take your foot off for. There's a little lever next to the brake that you can engage while it's depressed that will hold it in place."
That lever next to the brake peddle is the parking brake. You have to have the parking brake set for the engine to start. You have to push the brake peddle down to get that parking brake to set. Once you push on the brake peddle to release it, the parking brake should release. If it does not, you need to see why....and not use the mower with it set.
"One more thing I forgot to mention is that the brake stays depressed. Normally you depress the brake and it goes back to normal when you take your foot off for. There's a little lever next to the brake that you can engage while it's depressed that will hold it in place."
That lever next to the brake peddle is the parking brake. You have to have the parking brake set for the engine to start. You have to push the brake peddle down to get that parking brake to set. Once you push on the brake peddle to release it, the parking brake should release. If it does not, you need to see why....and not use the mower with it set.
Re: White smoke starts to we'll up under engine after running for a few minutes
Ok so I got some pics. I wanted to make sure there wasn't a head gasket problem so I tooknow the engine apart. My neighbor looked at it and said it looked fine. I did one of those tests where you check the blue liquid if it turns yellow and it seemed to be less than blue as I was doing it.
Ok so I got some pics. I wanted to make sure there wasn't a head gasket problem so I tooknow the engine apart. My neighbor looked at it and said it looked fine. I did one of those tests where you check the blue liquid if it turns yellow and it seemed to be less than blue as I was doing it.
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Re: White smoke starts to we'll up under engine after running for a few minutes
Coolant contaminated by combustion will change the color of the test fluid. I have a test kit and it takes so little to turn color its remarkable. Just blow in the tester.
Coolant isnt getting into the cylinders as they are all sooty. One cylinder should be clean, no soot just washed clean like it was steam cleaned. And if it wasnt overheating every time you run it then its safe to presume its not a head/head gasket problem.
Coolant contaminated by combustion will change the color of the test fluid. I have a test kit and it takes so little to turn color its remarkable. Just blow in the tester.
Coolant isnt getting into the cylinders as they are all sooty. One cylinder should be clean, no soot just washed clean like it was steam cleaned. And if it wasnt overheating every time you run it then its safe to presume its not a head/head gasket problem.
Re: White smoke starts to we'll up under engine after running for a few minutes
I got the engine back together and now it's reving slow and not turning over. At first I noticed the fuel injectors were leaking so I tightened them. Still having same issue. Is there something I might have missed putting it back together?
I got the engine back together and now it's reving slow and not turning over. At first I noticed the fuel injectors were leaking so I tightened them. Still having same issue. Is there something I might have missed putting it back together?