HOT UTV...Kubota Diesel

[6string]

i've got the 1140 and it was running warmer than usual.

in my case, my rad was plugged so i blew it out

A neighbor I used to work for has an 1140 with cab ac/heat. I would use it often and in midsummer pasture grass seeds would stop up the radiator fins pretty quickly. Normally ran very cool. The air conditioner condenser would get it too and it wouldn’t take long to figure that out of a hot day.

 

[DieselBound]

No fans running means you need to address this problem FIRST. Easiest/first thing to do is check fuses and look over the visible wiring for any signs of trouble. Check that the fan(s) can be turned by hand (engine and ignition OFF!). If they/it turns w/o and gravely sounds then check for a short in the motor(s): simple continuity check. Continuity check on the wiring to the fans might be tough, but in general at least do a visual inspection (rumors are that rodents can attack wiring).

Not a bad idea while it's got your attention to blow out the radiator fins. Do some regular maintenance stuff. Check that your coolant is still good. Is the water pump circulating coolant? Did you recently change or add coolant? (sometimes air pockets can get into your system and create an airlock) One of the "possibles" after all else has been addressed is the radiator cap (no holding pressure). Thermostat is a consideration, though we shouldn't even be thinking of this without first resolving the fan issue.

 

[Grandad4]

Obvious starting point is cooling system issues. As mentioned, the radiator cores on these little diesels can pick up very fine debris (dust, seeds, chaff, etc.), and they want to be cleaned out periodically. I did mine once or twice a year... if you run through unmowed fields frequently you might need to do it more often. I preferred an ordinary garden hose (cold engine of course!), but compressed air works also.

If you still have overheating after sorting out any cooling system issues, there are other possibilities. Is anything binding or slowing the drivetrain? Tires low on air? Brakes dragging?

You mention very steep terrain. I've seen hydrostat tractors have trouble on trails that were so steep the internal line that draws fluid for the hydraulics was drawing air, not hydraulic fluid. Must admit I don't know how steep it would have to be to cause something like that in an RTV. A hydraulic reservoir that is low would trigger such problems sooner, of course.

 

[Jerry/MT]

Guys, my 1year old Kubota RTV...1120D (Diesel side by side) overheated climbing a hill. I've climbed that hill several times before. Sometimes the electric cooling fan comes on but this time I got a red light and warning buzzer. The guage was alarmingly high. The coolant is full, the fan works.....???? Is there a larger radiator available? How about an ADDITIONAL elect fan? Ideas? BTW, the air temp was about 80....

Lot of good advice here but it seem to me you are depending on a electrical sensor (light and buzzer) to tell you it's hot. I would use an infrared thermometer on the top of the radiator (assuming it's metal) to make sure it is really overheating and it is not a bad sensor. If it is overheating, then cleaning the radiator is the first thing I would do. A bad fan sensor/control circuit, stuck closed thermostat, a slipping water pump drive belt, bad rad pressure cap, bad water pump, etc would be other considerations.

Good luck.

 

[RancherGuy]

Replace the water pump and t-stat "YESTERDAY". It's a routine maintenance item that get's overlooked. Even if not worn the impeller might be slipping on shaft.

What? It's a year old. Annual replacement of pump and thermostat is not routine maintenance.

 

[Boeing]

I was/am having an overheat issue that I posted before. I had checked the coolant and the radiator, both OK.
After searching for the thermostat I DISCOVERED that there is a SECOND radiator. Yup, belt driven fan on the front of the engine pulling air thru another radiator. Who knew???? (Access is thru plastic panel under SEATS) The front radiator has electric fans and is easy to access.
BTW.....WHERE is this thermostat????? Thx

 

[RancherGuy]

I was/am having an overheat issue that I posted before. I had checked the coolant and the radiator, both OK.
After searching for the thermostat I DISCOVERED that there is a SECOND radiator. Yup, belt driven fan on the front of the engine pulling air thru another radiator. Who knew???? (Access is thru plastic panel under SEATS) The front radiator has electric fans and is easy to access.
BTW.....WHERE is this thermostat????? Thx

FYI, the front is the radiator for coolant. The one under the seat is to cool hydraulic fluid. My first RTV was Gen 1 where the radiator was under the seat - nothing in the front. So I knew that I should keep it's screen clean, but one day it kept overheating and I couldn't determine how to check if it had enough coolant ... then one day I discovered the radiator in the front. Boy did I feel like a fool.

 

[Boeing]

Well, it's overheating AGAIN. I noticed that the elect fan IS NOT operating. It had been....but stopped? I popped the hood, rad super hot, coolant resoirvoir COLD (?). I looked for the elect fan but it must be shrouded top and back cause cannot see or feel. I wanted to "hot wire" the fan to verify operation. Then look for.....temp sensors? Fan relay? Duh...or leave it hot wired with a switch Ideas? Thanks

 

[5030]

i've got the 1140 and it was running warmer than usual.

in my case, my rad was plugged so i blew it out

Go buy yourself one of those Bauer 20 volt shop blowers and blow the rad out. Good unit, lightweight and really blows.

 

[ruffdog]

You need a radiator that is able to transfer heat from the liquid to air flowing through the fins. For this to work, you need clean fins (check with light behind) , flow of coolant, flow of air. Can you pull the radiator cap when running and see the liquid churning? If not, pump and thermostat is suspect. Have you checked that the fins are not plugged?