Mowing Kubota diesel overheating.

[4570Man]

I’m pretty sure that’s not his problem, he would notice a cylinder dropping out also. The problem occurs when a injector over fuels a cylinder and causes it to get hot.

The engine runs good, the exhaust is clean, the power output is good, I’m confident the water pump is good. I don’t think there’s anything wrong with the engine.

 

[sandman2234]

View attachment 702614

It must be dirty, as I can't see thru any of the fins in this picture, lol!!
David from jax

 

[Midniteoyl]

I took the radiator out and cleaned it. It looks pretty clean but on close inspection there was quite a bit of trash in it. I’ve cleaned it, put a new fan belt on, new thermostat in and I’ve got some chemical radiator flush to go in after I put it back together.

Straighten as many fins as you can as well while its out.

 

[ROUSTABOUT]

It seems to be circulating otherwise the radiator wouldn’t be hot. At least that’s my logic.

No, the impellers corrode off water pumps. They will kind of circulate. If you had no water pump at all, the radiator would still get hot just from heat rising. Does it crank evenly? Any smoke?

 

[4570Man]

Today I removed and cleaned the radiator, which had a surprising amount of dirt in it, installed new thermostat, installed new fan belt, did a chemical flush and put everything back together. And it was running cool until a leak in the lower hose drained the radiator. But I think it’s working properly now.

 

[Williy]

Midniteoyl I know that in my car without anti-freeze
would over heat and with a 50/50 mix was OK! I
only use distilled water in radiator. So what are
you trying to tell me???

willy

 

[4570Man]

And I came to an accidentally discovery of why running straight water is a bad idea aside from corrosion problems. You can smell leaking antifreeze from a mile away. But with the water I had no indication it was leaking. It’s a rear engine so you’d never see it. Luckily it was a slow leak and the temperature gauge registered the rising temperature. But the temperature gauge requires coolant to work and if a catastrophic leak dumped the coolant you’d never know it before it was too late.

 

[4570Man]

No, the impellers corrode off water pumps. They will kind of circulate. If you had no water pump at all, the radiator would still get hot just from heat rising. Does it crank evenly? Any smoke?

If the radiator was cooling as designed but the coolant wasn’t circulating as designed the radiator would never get much above ambient temperature. The radiator is designed to loose heat rapidly so what little heat it would collect from non circulating coolant would easily be cooled. You’d never get a 190 degree radiator which mine was with a bad water pump and functioning fan and radiator.

 

[Williy]

I read that the Brits say the aluminum & plastic
radiators are throw aways and some other
Brits said K-seal works great for fixing leaks

willy

 

[Hay Dude]

It must be dirty, as I can't see thru any of the fins in this picture, lol!!
David from jax

Ahhhh yeah that kind of obstruction will cause a wee bit of overheating lol
My tractor rads get a deep cleaning 1-2 times/year. Hay chaff and dust builds up to the point where any exterior obstruction on the hood causes temps to hit 200 and more.

 

[4570Man]

I read that the Brits say the aluminum & plastic
radiators are throw aways and some other
Brits said K-seal works great for fixing leaks

willy

Most plastic radiators run the life of the vehicle or equipment they’re in without repair. And the ones that don’t were probably damaged. No radiator is very resistant to getting a stick rammed through it.

 

[MiserableOldFart]

I wonder if anyone is using Evans permanent waterless antifreeze? I used it in my TC26DA once the warranty was up. It's expensive, and requires a flush with its own special flush stuff prior to putting it in, but it has no water, claims to be permanent for the life of the engine. It is a little more viscous than 50/50 and can run a little hotter, they say, but saw no difference in my tractor. It's also based on propylene glycol, less toxic to animals if there is a leak. They claim no rust or corrosion without the water in your system.

 

[CausticUrbanCoast]

I wonder if anyone is using Evans permanent waterless antifreeze? I used it in my TC26DA once the warranty was up. It's expensive, and requires a flush with its own special flush stuff prior to putting it in, but it has no water, claims to be permanent for the life of the engine. It is a little more viscous than 50/50 and can run a little hotter, they say, but saw no difference in my tractor. It's also based on propylene glycol, less toxic to animals if there is a leak. They claim no rust or corrosion without the water in your system.

You would have to buy the powersport version for a high aluminum system at twice the cost of a regular system.

 

[curmudg]

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.

 

[curmudg]

Agree with those saying a good flush. Use a de-scaling flush product following directions, then flush that out thoroughly with clean water and then refill systems with proper Antifreeze mix using distilled water.
I had similar problem with my reliable old diesel in GF1800 mower. When draining make sure you have both the radiator drain and the engine drain ports open and make sure block is draining - I had to fish a bit of 12 gauge wire up the blockdrain to unplug it.

 

[Username Taken]

Wrong. AF also raises the boiling point and helps the seals. If the engine has liners it helps the water side of them as well from pitting.

Well...... You're mostly right. What raises the boiling more than anything is the pressure in the cooling system. The AF certainly does help; it increases the boiling point, under 15 lbs of pressure, by about 12 degrees. From about 250 degrees for purre water to about 262 for a 50-50 mixture. Depending on altitude.

AF also inhibits rust in a big way. That's a biggy.

Those race cars you see flying around the track at 200 MPH for hours on end? They don't allow Antifreeze in those cooling systems that I'm aware of. If there's a wreck (imagine a wreck in a car race!!) the antifreeze ruins the track. Can't get it cleaned up enough to be safe. Maybe they have coolants now that do that but I don't think you and I want to pay what they sell for.

Not sure about F1. Those people are a little wierd anyway. I like F1, I don't like its premise.

 

[Username Taken]

The engine runs good, the exhaust is clean, the power output is good, I’m confident the water pump is good. I don’t think there’s anything wrong with the engine.

I've seen people replace their radiator cap and solve an overheating problem. They're more important than you think

 

[CausticUrbanCoast]

AF also inhibits rust in a big way. That's a biggy.
[ /QUOTE]

In a high aluminum cooling system standard coolant causes internal aluminum oxidation and corrosion. The channels will clog up internally and the outside will look fine.

"Coolant pH should always be maintained between 8.5 and 11. If a coolant’s pH drops below 8.5, it will become aggressive to ferrous metals (cast iron and steel), aluminum, copper and brass. If it increases above 11, it will
become aggressive to aluminum and solder in a cooling system."

From: https://penray.com/resources/cooling-system-tech-facts/metal-corrosion/

Standard coolant only cares about about the lower PH buffering threshold as it is cheaper to make and there are less domestic USA aluminum systems. Euro and Asian import spec coolant buffers both sides as they commonly produce aluminum blocks now.

 

[sandman2234]

I've seen people replace their radiator cap and solve an overheating problem. They're more important than you think

A simple radiator pressure tester will check the radiator for leaks or the radiator cap for the correct pressure.(with proper adapter). No sense throwing out a good cap. If you don't have the right tools to work on your tractor, you just become a parts changer.
David from jax

 

[lineman1954]

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.

did you find the problem ?