Kubota TG1860 Diesel continually overheating

[longdropping]

I have a Kubota TG1860 Diesel with the 3cyl 722D engine. I've replaced the radiator because when I first got the tractor the top of the radiator was blown off. Then, I replaced the head gasket and all the top end gaskets along with it because my assumption (which I believe was correct because gasket had failed) was that the head gasket failing, with help from a ridiculous amount of buildup blocking coolant passage ways and pressure relief points, caused too much pressure and resulted in the top of the radiator blowing off. Completely flushed the whole system, checked to make sure thermostat opened properly and made sure water pump was working properly. And just for some clarity, I used to be a diesel mechanic and I grew up working with/out of my dads diesel repair shop. I'm aware it could potentially be a cracked cylinder head and I'm just trying to figure out if there were any other possible reasons since I am not too familiar with Kubota. So if anyone has had any similar issues or know of any other potential causes please let me know! I'm just trying to avoid spending another $400 on top end gasket kit and head bolts! Thanks in advance!

 

[lmichael]

When you indicate it's over heating are you saying it's temp is actually rising to the danger point? Or because you have excess pressure buildup in the cooling system? If you're seeing bubbles in the system with engine cold you likely have a cracked head. Again at this point I am assuming you checked the deck for being flat, checked the head for warpage, etc. As if the deck is not flat or head is warped it's not gonna seal no matter what you do. But, from your description I'd guess it's cracked

 

[longdropping]

When you indicate it's over heating are you saying it's temp is actually rising to the danger point? Or because you have excess pressure buildup in the cooling system? If you're seeing bubbles in the system with engine cold you likely have a cracked head. Again at this point I am assuming you checked the deck for being flat, checked the head for warpage, etc. As if the deck is not flat or head is warped it's not gonna seal no matter what you do. But, from your description I'd guess it's cracked

It’s not from pressure. It does perfectly fine for 20-30 minutes then just gets outrageously hot. The water is boiling when it’s shut off. Not the appearance of boiling from pressure, I pull both caps off to relieve pressure and it continues to boil.

 

[longdropping]

It’s not from pressure. It does perfectly fine for 20-30 minutes then just gets outrageously hot. The water is boiling when it’s shut off. Not the appearance of boiling from pressure, I pull both caps off to relieve pressure and it continues to boil.

I don’t necessarily mean it’s not from pressure, not throwing that completely out, but when cold it does not bubble so assuming not pressure related at cold. Could still potentially be a cracked head and it just becomes noticeable when the head warms up and expands.

 

[lmichael]

Still thinking something cracked or warped.

 

[longdropping]

That’s what I’m figuring as well just hoped somebody had something else to try. Lol. Thanks!

 

[davidon]

Any further confirmation on this? I have the exact same problem of boiling when shut off. But have not done any part replacement or checks yet. Should I start with cap and thermostat?

 

[lmichael]

Any further confirmation on this? I have the exact same problem of boiling when shut off. But have not done any part replacement or checks yet. Should I start with cap and thermostat?

Boiling (bubbling) at shut off is not always the result of running too hot. Could be bad pressurization as well. Get yourself a cooling system pressure tester and cap tester. You can get one at Harbor Freight (take your pick from this link Harbor Freight Tools – Quality Tools at Discount Prices Since 1977 )
Or just simply buy a new cap and give it a whirl. But a bad cap can definitely cause a system to "boil up" at shut down

 

[Mike1955]

Imicheal also the coolant and water ratio need to be right. His sounds like it’s getting low after a short time period. Also I believe it would smoke white if the head was cracked. Just my thoughts

 

[lmichael]

Imicheal also the coolant and water ratio need to be right. His sounds like it’s getting low after a short time period. Also I believe it would smoke white if the head was cracked. Just my thoughts

How could the ratio change?