Overheating

Blitzz

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Kubota L295, St30, kobelco sk200-3lc
Oct 22, 2021
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Babados
Before you start removing items and assuming things to be "bad" -------- fill it up with good old water ........

run the hell out of it - get it hot .......... and please check those numbers............ if you can get the fluid cooled at the bottom of the radiator at or below 120 F then I would let her run as is.

Also - running an engine without a thermostat is a big no-no ....... why you ask, the water NEEDS to be slowed down a bit as it runs by the heated surfaces.... plus the engine needs to get to temp as quickly as possible to be "efficient" - a cold running engine is another no-no

And just because it was made in Turkey ..... does not make it "bad" - hell who knows, might be well made, then again maybe not - aint but one way to find out!

EDIT - what is the PSI on the cap btw?

It has a 14 psi cap on it, I 100% agree with the thermostat needing to be in, but it seems everyone down here just removes it as the very first thing

Have you confirmed the temperature gauge is accurate? Water boils at approx 210F so placing the sending unit in boiling water should be an easy confirmation. (It would be necessary to provide proper electrical “ground” to the engine block.)

Two things come to mind:

1- Is your radiator CAP also new? and it good condition? and the proper pressure? (By pressurizing the system the boiling point is decreased.)

2-While I’ve never witnessed this and find it curuious… Responsible sources claim that operating without a thermostat can contribute to overheating because the lack of thermostat allows the coolant to “rush” through the radiatior resulting in insufficient “dwell” or “time” in the radiator to remove heat. A thermostat not only brings the temp up quickly to proper operating temperature…it also regulates coolant flow through the radiator.
I will check the accuracy of the temp gauge, it is a brand new temp gauge but I will check it. Willing to do anything at this point, grass needs cutting asap.

EDIT; Yes, new cap
 

85Hokie

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It has a 14 psi cap on it, I 100% agree with the thermostat needing to be in, but it seems everyone down here just removes it as the very first thing



I will check the accuracy of the temp gauge, it is a brand new temp gauge but I will check it. Willing to do anything at this point, grass needs cutting asap.

EDIT; Yes, new cap
Without beating the dead horse ........ we can test all pieces of this puzzle - but that infrared thermometer will be plus or minus about 2 degrees F - which will not make a hillbilly damn in the grand picture,

Temps entering and temps exiting ........... now you can take temps at the thermostat housing too or filler neck or anywhere else you wish. But untill YOU know the temps ......everything else is guessing.
 

ruger1980

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L4310 w/La682, L225
Oct 25, 2020
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Have you confirmed the temperature gauge is accurate? Water boils at approx 210F so placing the sending unit in boiling water should be an easy confirmation. (It would be necessary to provide proper electrical “ground” to the engine block.)

Two things come to mind:

1- Is your radiator CAP also new? and it good condition? and the proper pressure? (By pressurizing the system the boiling point is decreased.)

2-While I’ve never witnessed this and find it curuious… Responsible sources claim that operating without a thermostat can contribute to overheating because the lack of thermostat allows the coolant to “rush” through the radiatior resulting in insufficient “dwell” or “time” in the radiator to remove heat. A thermostat not only brings the temp up quickly to proper operating temperature…it also regulates coolant flow through the radiator.
1- I believe you mean pressurizing the cooling system increases the boiling point

2- Coolant flow is not the issue most people think it is. More important is the ability of transfer of heat from the block engine to the coolant and from the coolant to the radiator. Also air flow through the radiator is key. One issue with removing the thermostat is that many diesel engines use the thermostat to block the coolant bypass when the thermostat is open. I know some Kubota engines have this feature and some do not.
 

North Idaho Wolfman

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Have you been judging the temps on just the original temp gauge?

Why was the engine rebuilt in the first place?

Fill the radiator full, then with the cap off, run it at an idle and look for a formation of bubbles in the radiator.
 

Blitzz

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Kubota L295, St30, kobelco sk200-3lc
Oct 22, 2021
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Babados
Have you been judging the temps on just the original temp gauge?

Why was the engine rebuilt in the first place?

Fill the radiator full, then with the cap off, run it at an idle and look for a formation of bubbles in the radiator.
No, brand new temp gauge, engine was rebuilt due to overheating/ low power/ low compression. New sleeves, pistons, rings, bearings, valves+seats and gaskets. Head was surfaced when he block was re-sleeved. Did the bubble check and there is no bubbles.
 

85Hokie

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No, brand new temp gauge, engine was rebuilt due to overheating/ low power/ low compression. New sleeves, pistons, rings, bearings, valves+seats and gaskets. Head was surfaced when he block was re-sleeved. Did the bubble check and there is no bubbles.

Good to hear on the bubbles! Now a tight engine will run a bit warm till all them parts get to know one another! :ROFLMAO:
 

Blitzz

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Kubota L295, St30, kobelco sk200-3lc
Oct 22, 2021
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I have the temps, one of my gauges isn't accurate at all but.
Temp gauge reading: 230 F
Upper tank next to hose: 213 F
Lower tank next to hose: 209 F

Checked and it has a 3 core radiator.
 

North Idaho Wolfman

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Did you have the head checked for cracks?
If it was overheating before then that's most likely the issue.
 

85Hokie

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That lower "tank" ..... I hope radiator is what you are referring to?

209 is reaaaaaalllll bad!!!!

Then maybe ....that radiator is .......... junk!


I know this sounds crazy - can you run those temps again?
 

Blitzz

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Kubota L295, St30, kobelco sk200-3lc
Oct 22, 2021
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That lower "tank" ..... I hope radiator is what you are referring to?

209 is reaaaaaalllll bad!!!!

Then maybe ....that radiator is .......... junk!


I know this sounds crazy - can you run those temps again?
Yes, the tanks on the radiator, top and bottom, I will go and take temps again
 

Blitzz

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Kubota L295, St30, kobelco sk200-3lc
Oct 22, 2021
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That lower "tank" ..... I hope radiator is what you are referring to?

209 is reaaaaaalllll bad!!!!

Then maybe ....that radiator is .......... junk!


I know this sounds crazy - can you run those temps again?
Just took the temps again and yep basically the same thing, took them at a lower temp this time but.

Gauge temp 210 F
Upper tank: 201 F
Lower tank: 198 F
 

dirtydeed

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Assuming no head cracks, have you checked the condition of the water pump/presence of air lock?

If the water pump belt is tight, could you try something like Redline Water Wetter? I ran it in my quads and it really seemed to help.
 

85Hokie

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Just took the temps again and yep basically the same thing, took them at a lower temp this time but.

Gauge temp 210 F
Upper tank: 201 F
Lower tank: 198 F

WOW .......

note to self .............. never buy a radiator from Turkey ..........

that is somewhat amazing the fact that there is almost zero cooling through a brand new radiator........

IS fan belt tight? Fan spinning as it should
 
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Blitzz

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Kubota L295, St30, kobelco sk200-3lc
Oct 22, 2021
26
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Babados
Assuming no head cracks, have you checked the condition of the water pump/presence of air lock?

If the water pump belt is tight, could you try something like Redline Water Wetter? I ran it in my quads and it really seemed to help.
it has in a new water pump and the belt is tight. I cant get redline water wetter but I can royal purple purple ice, which I might try.
WOW .......

note to self .............. never buy a radiator from Turkey ..........

that is somewhat amazing the fact that there is almost zero cooling through a brand new radiator........

IS fan belt tight? Fan spinning as it should
belt is tight, fan is spinning as it should and is moving good air.

Anyone know how many cores a oem rad has?
 

ruger1980

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L4310 w/La682, L225
Oct 25, 2020
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Like @007kubotaguy said is the shroud intact and positioned correctly if it has a shroud. Also is the fan oriented correctly. If installed the wrong way it will not pull enough air through the radiator.
 

Quick

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Just took the temps again and yep basically the same thing, took them at a lower temp this time but.

Gauge temp 210 F
Upper tank: 201 F
Lower tank: 198 F
If you're SURE the water pump is good, it sounds like you've got blockage somewhere.
 

Blitzz

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Kubota L295, St30, kobelco sk200-3lc
Oct 22, 2021
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Babados
If you're SURE the water pump is good, it sounds like you've got blockage somewhere.
If there were to be a blockage where would it be, when the thermostat was out there was really good through the rad. I honestly have a feeling its the cheap radiator, you can basically look right through the thing.

Like @007kubotaguy said is the shroud intact and positioned correctly if it has a shroud. Also is the fan oriented correctly. If installed the wrong way it will not pull enough air through the radiator.
The shroud is in good order and the fan is in the correct orientation.
 

Mark_BX25D

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Bx25D
Jul 19, 2020
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and please check those numbers............
Exactly. Until you confirm with some kind of known good thermometer (IR gun or otherwise), you don't know you have a problem.


Also - running an engine without a thermostat is a big no-no ....... why you ask, the water NEEDS to be slowed down a bit as it runs by the heated surfaces.... plus the engine needs to get to temp as quickly as possible to be "efficient" - a cold running engine is another no-no
I noticed this earlier and was going to comment, but got sidetracked.

If the coolant doesn't spend enough time in the radiator, it won't shed enough heat and won't get cool enough. It's called, "dwell time".

Don't assume there is something wrong when you aren't even running it according to design.

On another forum, we've seen poeple (usually a kid) one after another spend hundreds of dollars on high flow water pumps, uber-custom radiators, lower temp thermostats, and still have an overheating problem.

Then they put it back to stock and the problem is solved.

Get the t-stat back in place, get an accurate measurement, then you'll know if you have a problem or not.

If you do, my money is on your gunked up block.


Cooling systems are systems, not just a collection of different components. They are designed to work together.