Mowing Kubota diesel overheating.

eddieirvine

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Kubota L 3940
Since no one mentioned it I will. Your lower radiator hose (suction) may be collapsing. Most have a spring reinforcement to prevent this but, some rely on the hose itself and when they get old they can close off from the suction.
good point Northcreek
 

dirttoys

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ac 170 bobcat 773 tak 235
If the thermostat is out, the radiator is not clogged, and the fan has its blades and spins when running (loose belts), it points to a water pump that the impeller may be slipping or have a shear pin that has been sheared or more likely the belt is broken/missing or too loose.
If the system is at least reasonably clean, the fan turns, and the thermostat is out, it is almost surely the water pump impeller or belt preventing the coolant from circulating.

Dane…
Respectfully disagree, you are correct that a water pump could do it. Given the age, and the feedback that water does flow in and out of block, if I had a single guess it would be plugged radiator. Core/replace, I give it 90% odds of cure.

Best,

ed
 

dirttoys

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ac 170 bobcat 773 tak 235
Have you considered a leak either in the head gasket, the seals between a cylindar and the block. Try using a sealer. You might have a leak so small it's undetectable in the exhaust. You've also indicated it seems to gert hotter with time, indicating engine expansion is expanding the leak. engine sealant - Google Search
My night to be a disagreeable turd, sorry. Stop leak in little diesels, with small water jackets should be a last ditch effort. And you should be aware you are taking a better than fair chance of making a small problem a big one.

Best,

ed
 
  
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4570Man

4570Man

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Hey 4570Man, what do you have against taking the Radiator to a shop ? 🏻️

I’ll probably take it out and inspect it when I have time but I don’t want to take it to the radiator shop because it would take a lot longer and probably cost as much as just buying an aftermarket one.
 
  
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4570Man

4570Man

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I really didn’t intend to start a 100 plus post debate about antifreeze. But the engine isn’t reaching the technical overheated definition. It’s maintaining the maximum allowable temperature and has a couple times triggered the over temp light. But it hasn’t a single time boiled out of the radiator. The water pump is 100 percent working. Changing the antifreeze mix to straight water did lower the temperature a little bit. The straight water still didn’t boil out.
 

5030

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Interesting about getting the rad recored. Never had either rad out of my M9's, ever. One is a 2002 with 2500 hours on it. The other is a 2004 with 6000 plus hours on it. I run Prestone 50-50 pre mix in both. I'd run straight water with Purple Ice if it didn't get below freezing here but it does, so I don't.

I do keep them clean, they get blown out every day when I come in from the field and at least weekly I use a Radiator Genie with water to clean the rad of any accumulated stuff that might be in there.

Of course I wasn't aware you could recore a radiator with sonic welded on plastic tanks top and bottom but then maybe you can. of you can I sure don't know about it.
 

5030

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The straight water still didn’t boil out.
It won't because the system is pressurized. Just like a pressure canner, the higher the static pressure is, the higher the boiling point becomes.
 

dirttoys

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ac 170 bobcat 773 tak 235
Interesting about getting the rad recored. Never had either rad out of my M9's, ever. One is a 2002 with 2500 hours on it. The other is a 2004 with 6000 plus hours on it. I run Prestone 50-50 pre mix in both. I'd run straight water with Purple Ice if it didn't get below freezing here but it does, so I don't.

I do keep them clean, they get blown out every day when I come in from the field and at least weekly I use a Radiator Genie with water to clean the rad of any accumulated stuff that might be in there.

Of course I wasn't aware you could recore a radiator with sonic welded on plastic tanks top and bottom but then maybe you can. of you can I sure don't know about it.
In an effort to be slightly more agreeable:) Not sure what can or can't be un-soldered cored and sealed back up, that is why I carefully said cored/replaced. All my older/bigger stuff is so over cooled it can probably work with 40-50% plugged radiator and still be fine. The little/newer stuff seems to fight so hard to save a buck and a pound, that everything is on razors edge. That is not a provable fact, just my observation.

Best,

ed
 

Midniteoyl

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Company says: Shell Rotella
  1. Protection against overheating – Excellent heat transfer properties allow heat to transfer more effectively, protect against freeze and boil-over and help keep engines running cool
willy

Who you gonna believe, Willy, the engineers or marketing?
 
 
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