Mowing Kubota diesel overheating.

[CausticUrbanCoast]

Reversing a fan blade won't change the direction of flow, only reduce efficiency due to the curve of the blades..

The image appeared to show little to no air movement on the the plastic bag, so it seems the drawthru might be impacted. The grasshopper ZT have went through a lot of engine combinations; difficult to know if this is original or a repower.

That was the only reason for the question of blade damage or reversal.

 

[4570Man]

Water freely flowing from one hose port or cap opening to other hose port, tells you absolutely nothing about water flow throw the small passages of then fins were cooling occurs.
I also noted that this is your response to seeing light through the air passages openings between the fins. All that dirt and dust and clippings when you mow are either pulled or pushed by the fan through the radiator. I would mot be s bit surprised to fund that you have issues in the fins—water passages or air passages if not both. Same symptoms with mo thermostat indicate one or both are issues.

I meant when you’re spraying the front of the radiator it easily flows through the face of the radiator and out the other side.

 

[4570Man]

The image appeared to show little to no air movement on the the plastic bag, so it seems the drawthru might be impacted. The grasshopper ZT have went through a lot of engine combinations; difficult to know if this is original or a repower.

That was the only reason for the question of blade damage or reversal.

It’s the original power unit to the best of my knowledge but it was used when I got it. The fan is running the only way to could. The radiator is 4” behind the seat and the operator would die of a heat stroke if it was the other way. I’m agreeing with the thought process that the interior cooling passages are clogged. The airflow through the radiator seems good and the water flow seems good but it’s not loosing enough heat.

 

[Midniteoyl]

I meant when you’re spraying the front of the radiator it easily flows through the face of the radiator and out the other side.

Clean from the to fan side out. Also need to get in behind that shroud. Bet there's gunk in them corners. Regular hose pressure isn't gonna cut it right now. You need to deep clean.

 

[northcreek2624]

Water pump would be another place that I'd look, could be a bad/broken impeller.

 

[4570Man]

Water pump would be another place that I'd look, could be a bad/broken impeller.

When I pulled the upper hose and started it it emptied the radiator in like 10 seconds so the pump is working good.

 

[Gord Baker]

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.

I suggest you replace the Radiator Pressure cap. Pressure in the system prevents coolant from boiling at 1 degree per 1 PSI. 10 lb pressure cap will allow coolant to go to 222° without boiling. Always use a correct thermostat.

 

[Jofang]

It's worth flushing the rad with a suitable rad flushing chemical, as the metal core of the rad may be c°°oated in alkaline deposits or other rubbish. To cool properly the water needs A,°to make contact with the metal core and it's possible that the crud inside your rad is acting like a thermal blanket.

 

[Riverside66]

I agree with your comments about the benefits of AF, but pure water transfers/conducts heat better than ANY ratio with AF. #fact

 

[Unclewillie]

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.

blow any grass stuck around the cylinder head with air pressure, that's assuming there are covers hiding the head and block.