Mowing Kubota diesel overheating.

[5030]

Do you have the right mix? water alone will
not work and anti-freeze needs water to work

willt

No, it don't Just went through that on another thread. Ordinary distilled water is the best heat transfer medium there is, much better than antifreeze in any concentration. The ONLY thing AF is good for is below freezing temps. Far as corrosion goes, add a bottle of Purple Ice or Water Wetter to the water. That gives it corrosion protection. That will cover the infamous water pump seal that don't exist any more too.

As a side note, race car drivers don't use AF at all, just plain distilled water with Purple Ice or Water Wetter.

Don't believe me, Goggle it up and find out for yourself.

 

[5030]

In hot weather, antifreeze keeps the water in your engine and radiator from boiling over and in cold
weather keeps it from freezing
JUST PLAIN FACTS!!!

willy

1/2 wrong and 1/2 right. AF lowers the freeze point but your rad cap raises the boiling point of the coolant, why the system is pressurized in the first place.

The OP may have a defective rad cap as well. Cheap Kubota part.

 

[4570Man]

So straight water without a thermostat = no over heating? What does that tell you?

I don’t think removing the thermostat helped anything, possibly made it worse. I’ll put one back in but I couldn’t get one over the weekend. My old one probably wasn’t bad but they’re not expensive. And the straight water can’t stay either since it gets below freezing here.

 

[the old grind]

I bought my Case/IH with a bum thermo'. I could tell right away by the gauge that it wasn't coming up to temp. (Man, was that oil dirty when I changed it the first time.) Anyway, opening temp won't matter if we're overheating. IMO that's kind of a lot of hours on a radiator, even if properly filled/monitored it's entire service life.

 

[Hay Dude]

I’ve got a grasshopper ZT with a Kubota diesel in it. It happens fairly slowly but the temp keeps creeping up. The radiator is clean. The air filter is clean, the fan belt is tight, the fan shroud is in place all but a little bit at the bottom which I don’t think has ever been there. There’s no fan clutch, it’s direct mounted. I’ve taken the thermostat out and ran without it and there’s no change. I put the thermostat in a pot of water and heated it on the stove and the pot was very near boiling before it opened. I honestly thought it would fix the problem taking that out but it didn’t. I might repeat that that test with a thermometer since it was supposed to open at 160 degrees. I’ve taken the side panels and hood off to see if better ventilation would help and it does but not a notable amount. And it blows more heat down my back that way. The radiator is as hot as the block when checked with an infrared thermometer. So it seems to me the radiator is taking heat but not loosing it. I’m pretty much at a loss on this one.

Have you deep cleaned the rad fins with a strong stream of water? Whenever one of my tractors temps won’t decrease after pressurized air cleaning, I know it’s time for a strong water rinse.

 

[ruffdog]

I would pull the radiator and clean the fin area so you can see through all of it.

If the water pump is working, apparently, the radiator is not getting rid of the heat.

 

[4570Man]

Have you deep cleaned the rad fins with a strong stream of water? Whenever one of my tractors temps won’t decrease after pressurized air cleaning, I know it’s time for a strong water rinse.

Yes I’ve washed it with a water hose and from a distance with a gentle pressure washer nozzle.

 

[5030]

If you really need AF, go with the 50-50 pre mix. They use pruified water when they mix it. I use Prestone green myself. In fact Kubota specs green (old style coolant).

 

[the old grind]

I premix/label for my climate at 50/50 with distilled water that I buy and use weekly along with drinking water and for $.89/gal. Reading labels for yrs it's stuck in my head that 33%-66% is recommended. 33% AF for warm climates, and I've read somewhere that 66% AF may be indicated for diesels to minimize cavitation an/or cyl liner wear where applicable.

I also use a refractometer to gauge acidity. Remember when the service station guy would use one before recommending a change? ('50s, '60s) Modern AFs (yellow/green, orange, 'gold') are typically formulated to protect alum components in car/truck engines from galvanic corrosion. The more noble alum will scale or corrode as coolant ages. A tractor that has no alum head, block, lower intake man, water pump, etc getting coolant flow can do ok with the old green stuff.

I can't imagine a cooling system being so fussy about the exact mix to do its job well. That said it's not just the fins that can need cleaning. Got aluminum radiator? It could be scaled up on the inside. I agree with suggestions that a flush may be needed based on hours & age.

 

[Wamman]

Put the proper thermostat in it. Take the radiator to a radiator shop and tell them to rod it out. They will take the tank off one end and run a rod downs through every flu. Probably has 2-3 stopped up. That’s all it takes. Then proper coolant mix. Make sure they rod it out not just flush. That should fix it.