A few random thoughts:
1. Is the mulcher just too much load for that engine? I wonder what Kubota's acceptable upper limit for EGT is prior to the turbo and what your EGT is running under this load.
2. Is the coolant pump/cooling system flowing as well as it should? With a 70-80 degree drop across the radiator, it is rejecting plenty of heat but the outlet flow to the radiator is too hot. If something is restricting the flow (thermostat not fully open) or if the pump blades have eroded (it happens to some engines with coolant that has gotten out of PH balance) then flow isn't what it ought to be. If coolant flow is the issue, then a radiator with more surface area but not much greater flow won't help that much and an auxiliary radiator in series with the main radiator could even make it worse.
3. Anything that restricts the exhaust more than design will create overheat in a hurry (deposit fouled muffler, distorted/crimped exhaust pipe).
4. What type of engine oil cooler is stock in this setup? If it is a oil to engine coolant exchanger, then it contributes significantly to the coolant temperature. Running this high of a coolant temperature would make me really want to know what the oil temperature is doing.
5. An additional oil cooler and/or a high flow radiator with more surface area could probably control the operating temperature. But if the stock cooling system is working as intended then you may find the next weak link (i.e. EGT leading to damage) if you overcome the cooling issue.
Good luck with this!
Rodger
Hi Rodger, thanks for the good input. I’m nit sure what the EGT temp is supposed to be before and after the turbo although, one Kubota dealer said the checked it and checked the turbo oil seal for leaks. They said Jorge were okay.
A few random thoughts:
1. Is the mulcher just too much load for that engine? I wonder what Kubota's acceptable upper limit for EGT is prior to the turbo and what your EGT is running under this load.
2. Is the coolant pump/cooling system flowing as well as it should? With a 70-80 degree drop across the radiator, it is rejecting plenty of heat but the outlet flow to the radiator is too hot. If something is restricting the flow (thermostat not fully open) or if the pump blades have eroded (it happens to some engines with coolant that has gotten out of PH balance) then flow isn't what it ought to be. If coolant flow is the issue, then a radiator with more surface area but not much greater flow won't help that much and an auxiliary radiator in series with the main radiator could even make it worse.
3. Anything that restricts the exhaust more than design will create overheat in a hurry (deposit fouled muffler, distorted/crimped exhaust pipe).
4. What type of engine oil cooler is stock in this setup? If it is a oil to engine coolant exchanger, then it contributes significantly to the coolant temperature. Running this high of a coolant temperature would make me really want to know what the oil temperature is doing.
5. An additional oil cooler and/or a high flow radiator with more surface area could probably control the operating temperature. But if the stock cooling system is working as intended then you may find the next weak link (i.e. EGT leading to damage) if you overcome the cooling issue.
Good luck with this!
Rodger
Rodger, Thanks for the great input.
1. One of the dealers noted that they checked the EGT on both sides of the turbo. They also said they checked the turbo oil seal, all three were okay. With this said. I'm not sure what the EGT temp is supposed to be.
2. Thermostat was replaced. Ive checked the flow inside the radiator and noted that after the thermostat opens, there is plenty of flow. aLthough I don't know how to measure the flow of the water pump. the machine only has 1800 hours on it. I would really be disappointed in Kubota if the water pump blades were depleted after 1800 hours. I'll order a gasket and pull the pump just to be sure.
3.Exhaust restriction: I'm totally with you on this. I mulched two days and the machine use 3-1/4 gallons of DPT fluid (wow). I've asked them to change the DPF system, so next week when the dealer has it, they are going to check the DPF system for blockage.
4. Great insight: No oil cooler on the machine. It does not have temp gage for the oil. I did look into one. A multi-temp gage is $1000.0 and checks four positions. I'm considering the purchase.
5. I'm not sure why I would need a different radiator and an oil cooler if there are plenty of machines out there that are not overheating running the same head. Last week, I checked with a radiator manufacturing shop to see if they could make a radiator. They said they wouldn't know where to start because the operation conditions of the machine are unknown.
Ill keep you posted.
Thanks