Bobcat 753 heat engine

[cahani]

I have Bobcat 753 BOSS model During work of 1-2 hours everything is normal But then a heat engine starts to rise what could be the reason? The temperature sensor is OK Without thermosetting and free flow of water Inside the radiator you see water passing through, that means a proper water pump. radiator after cleaning I can not find the root cause Can anyone advise?

 

[Tazza]

You said you can see coolant moving in the radiator, are the fins clear to allow air to blow through it?
It may be an idea to get hold of a hand held thermometer to see what the actual engine temperature is. You can get IR ones off ebay pretty cheap to ensure it is not getting too hot.
Do not allow your engine to get too hot, Kubota engines do not like being over heated, you have done the right thing looking to find the cause of the warning.
Another thing to check is the belt that turns the blower, if it's bad or the gearbox is bad, it will not blow air through the radiator.

 

[cahani]

You said you can see coolant moving in the radiator, are the fins clear to allow air to blow through it?
It may be an idea to get hold of a hand held thermometer to see what the actual engine temperature is. You can get IR ones off ebay pretty cheap to ensure it is not getting too hot.
Do not allow your engine to get too hot, Kubota engines do not like being over heated, you have done the right thing looking to find the cause of the warning.
Another thing to check is the belt that turns the blower, if it's bad or the gearbox is bad, it will not blow air through the radiator.

Coolant as it should be Radiator after cleaning and releasing fillings There is no thermosetting so there is free flow of coolant I also put a mechanical thermometer in the engine and it shows the same thing as a watch panel I'm afraid it's something to do with a hydraulic oil ridator because it does not understand why it takes a long time until the heat starts to rise and then it does not go down even after a break of half an hour it immediately returns to climb upwards in 5 minutes

 

[Tazza]

Coolant as it should be Radiator after cleaning and releasing fillings There is no thermosetting so there is free flow of coolant I also put a mechanical thermometer in the engine and it shows the same thing as a watch panel I'm afraid it's something to do with a hydraulic oil ridator because it does not understand why it takes a long time until the heat starts to rise and then it does not go down even after a break of half an hour it immediately returns to climb upwards in 5 minutes

The oil cooler fins are clear too? If the radiator fins and the oil cooler fins are clear, the fan should move enough air to cool the radiator without any issues.
As you have removed the thermostat, you have plenty of flow through the radiator which should do the job.

 

[cahani]

The oil cooler fins are clear too? If the radiator fins and the oil cooler fins are clear, the fan should move enough air to cool the radiator without any issues.
As you have removed the thermostat, you have plenty of flow through the radiator which should do the job.

That's exactly the problem I can not figure out the root of the warming issue especially that the oil radiator fins and the radiator fins are free of dirt. There is good air flow and the thermostat is dismantled in favor of a larger water passage. The engine still warms after 1-2 hours and since then it has always remained at high temperature even after a half hour break

 

[Tazza]

That's exactly the problem I can not figure out the root of the warming issue especially that the oil radiator fins and the radiator fins are free of dirt. There is good air flow and the thermostat is dismantled in favor of a larger water passage. The engine still warms after 1-2 hours and since then it has always remained at high temperature even after a half hour break

The only other thing i can think of is that the internals of the radiator could be blocked? It could cause coolant to not go through the radiator fast enough to get the heat away.
I assume you have a lot of air flow out of the air vents? and it should be nice and hot air?
An internally plugged radiator is really the only thing left.

 

[cahani]

The only other thing i can think of is that the internals of the radiator could be blocked? It could cause coolant to not go through the radiator fast enough to get the heat away.
I assume you have a lot of air flow out of the air vents? and it should be nice and hot air?
An internally plugged radiator is really the only thing left.

The radiator after dismantling, cleaning and moving its way through, and reassembly without any special problems everything was clean but still the problem of warming back

 

[Tazza]

The radiator after dismantling, cleaning and moving its way through, and reassembly without any special problems everything was clean but still the problem of warming back

Sadly i don't know what else to check. If the radiator is moving coolant and air flow is good, there is no reason for it to over heat.
If you put your hand on both sides of the radiator, can you feel if one side is a lot hotter than the other? it may indicate an internal blockage.

 

[oracle_of_ferndale]

The radiator after dismantling, cleaning and moving its way through, and reassembly without any special problems everything was clean but still the problem of warming back

What temperature is your engine running at? My temperature gauge does not have numbers, it just has green and red. It heats up slowly (just like you describe) and creeps into the red area after about 30 minutes. It does not seem to cool off quickly either.

After testing and changing a bunch of parts, I tried the IR thermometer and learned that the engine block was only 160 degrees when the gauge shows red. Probably too cold for the engine to run well.

For now I am just checking the temp every so often while running the machine. Next chance I get, plan to replace the temp sender and gauge, and reinstall the thermostat.