Kubota Skid Steer Overheating

​OVERHEATING DESCRIPTION:
Below is a great read. It is my painful journey in the attempt to use a Kubota SVL95-2 High Flow skid Steer to mulch vegetation. Four Kubota dealers have tried to solve the problem. I also had extensive help from Loftness Mulchers, and some assistance form FECON Mulchers. I have discussed the overheating problem with over 100 great folks, who have contributed time and money trying to stop the overheating problem. They have been nice enough in communicating back to me on their journeys. Good luck and stay safe.

 

Kubota Over Heating Journey
I'm running a Kubota SVL95-2S with high-flow. Attached is a Battle-Ax mulching head (carbide teeth) with an external Loftness dual fan cooler, Only while running the mulcher, the machine engine temperature continually increases until "Hot" warning sounds off (code: 9114). If I let it cool to where the temperature reading is in the middle of the gage and begin mulching; it only takes an average of four minutes to eleven minutes to overheat to reach a high point and sound the E9114 alarm. Hydraulics stay a cool 175 degrees. The coolant is running around 237°F.
Through this 5 year journey, after my warranty was up, Kubota abandoned me. I email letters to Kubota Corporation for help with the over heating problem. I received no reply (shameful). I have two Kubota's. I will never own another.
If anyone would like to talk to me about this problem, please feel free to call me at 931-292-0145 (Three Oaks Property Management). My name is Mike Stolarik

8/17/25: Deleting the DEF System (Latest attempt to solve the problem)

I decided to delete the DEF system (Cost: $3000.00). I did it the correct way. I sent both the ECM and the ACM out to be reprogramed so that neither computer would see any portion of DEF system or any of its electronic components. I removed every single piece of the EGR system i.e. DEF Filter, muffler, DEF holding Tank, DEF pump. I also removed all metal brackets that hold or retain and portion of the DEF, EGR, ACR System, EGR valve and housings, I removed the EGR metal transfer tube. I also removed the EGR air cooler which is located in the right side of the engine. It is connected to the exhaust manifold and the coolant system. I blocked off plate, and two coolant line plugs which needed to be machined. I Fabricated a new stainless steel 2 inch exhaust with a muffler.

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Result: After removing the DEF system, my Kubota SVL95-2 still over heated while using a vegetation mulcher. The additional 20% is noticeable but not a magnificent game changer. Overheating took longer and the engine compartment did not heat to 200°F+ as fast as it normally did. With the mulched off, the engine compartment cooled down faster. I was able to change my style of mulching and manage the overheating although it was at the cost of time which took longer to complete the job. The engine still overheated up to 204°F (then I stopped Mulching). At the 204°F, I slowed the mulching proceed and only mulched light underbrush until the engine cooled back down to 195°F to 198°F I then began mulching trees again. If the ambient temperature is less than 80°, it takes much longer for the engine to overheat.  

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4/1/25: The story of the new engine and the reason why the original engine blew up.

The skid steer motor destroyed itself and caught fire. I was able to put the fire out quickly, so there was no damage to the machine, just the engine and a few wires.

The reason: there is a "overflow fuel rail" inside of the valve cover (Part #: 1J574-42500, 1J57442500, K1J574-42500, K1J57442500). It connects to all of the injectors. At each injector, there is a banjo fitting which allows you to bolt the overflow fuel rail to the injector. Kubota pressed each tube into the banjo fittings. The vibration of the engine, caused one of the tubes that is presses in the banjo fitting, to loosen and begin pushing diesel fuel into the crank case. As the crank case filled with diesel, the diesel saturated oil became more flammable. This made the hot side of the turbo bearing catch fire push the super heated oil back in to valve cover, igniting an internal engine fire, which lead to the disaster.

Most manufactures TIG weld the metal line into he banjo fittings. Again, cost savings and poor engineering caused a Kubota to fail. Total cost to replace the engine: $26,530. I purchased the new engine. I removed the blown engine and replaced it with the new engine. I then took the skid-steer to Kubota to fine tune the engine. After weeks of labor and numerous attempts at the cost of replacing other components, they discovered the bad overflow fuel rail  

Total down time:

Time it took me to R&R engines: 2 days ($12,384).

Time it took Kubota to get the motor to run correct: 39 days. (Kubota cost: $14,149). It took them that long to find that the bad overflow tube was leaking.

After replacing the engine the machine still overheated while using the vegetation mulcher. 

PREVIOUS NOTES AND TIME LINE:
The below items CAN cause the SVL95 to overheat:

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1. Remove the complete DEF system. Send ECM and ACM out for reprograming. Engine still over heated but overheating was someone what manageable. 

2. Replace complete engine: Engine still had the overheating problem

3. Radiator: between the fins must be kept clean. Every three months, fins should be cleaned with a product such as Nu-Brite A/C fin cleaner. Remove the radiator, lay flat on saw horses. Spray the top side with Nu-Brite until the Nu-Brite can be seen running out of the opposite side. Be generous with the Nu-Brite. When clean, you should be able to see a small amount of light between the fins. Remember the fins are in a Zig Zag pattern so you will not see "Full" light. Check for bent fins on the engine side of the radiator.

4. Motor venting clean and clear. Including the lift arm vents. Remove the door behind the tracks (four bolts. Only the top two bolt will come out all the way.

5. Radiator is full of Antifreeze.

6. I changed my radiator cap to a 18lb cap it increase the boiling point.

7. Injectors all tested and changed (running rich). Installed new injectors.

8. Clogged hydraulic fluid filters.

9. Dirty Air filter.

10. DEF full, only use high grade.

 

Ancillary Checks:

1. Does it over heat at 3/4 or full throttle.

2. Try different high flow setting right side 1-14 and left side from 1-9.

3. Check temp of mulchers hydraulic hoses. I'm using mulcher with external dual fan hydraulic cooler. (Both fans running). The the ambient air is 95 degrees the hydraulic lines 127-137 max degrees.

4. A/C condenser clean and full light can shine through.

5. The inside of the machine is spotless with no debris in the bottom or in the lift arm cooling stacks.

6. Lift arm top openings not blocked.

Historical Information of the overheating problem

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9/1/2024:

Tighten the alternator/fan belt so tight that when you turn the fan with your had, the crank pulley also turns. If the crank pulley turns a little then stops, tighten the alternator belt a little more. I have had a number of folks try this and it is working for most folks but no all. I also change the radiator cap to a 18lb to increase the boiling point of the antifreeze to 225 degrees. On 4/25/21, my problem began when I had a vegetation mulcher and cooler attached to the machine. On 8/17/25, some progress has been made but a solid cure is still not in sight.

6/26/24: Although this did not cure my problem, I have discovered that; even after installing the protection grid over the inside of the radiator, the radiator fins continue to be flattened by debris. The flattening of the fins stops air flow which causes over heating. I have found that every 4-5 months, I have to pull the radiator and straighten the fins and clean the radiator with Nu-Brite. I also run a 50/50 mixture of antifreeze and distilled water. It has been proven that distilled water dissipates heat better than tap water.

10/3/23: Over heating is still present although it occurs sooner. I discovered that I have gotten another piece of wood caught between the fan and the radiator. The piece of wood beat the radiator fins flat. I remove the radiator to straighten fins. Kubota sells a screen that prevents this from happening ($1000.00). I made my own out of 1/2 inch live stock wire. Overheating problem still occurring.

7/23/22, Bent radiator fins straightened: I completed a full 10 hours of operation and the skidsteer did NOT overheat. Even though ambient temp was +90 degrees. The temp gage did not reach the 3/4 mark. This worked for about three months, then it began over heating again. Something changed! Side note, I had taken the fan off when I removed the radiator.

7/11/22, Although this did not help, while at Kubota dealer, a mechanic noticed that the fan orientation was not correct. It was put on backwards when they installed the hydraulic cooler. The end of the fan blade has an extension or what I call a teardrop on the outer-end of the blade. please a fan blade is at 12 o'clock. The teardrop on the end of the fan blade should be facing the "1:00" position NOT the "11:00" position. Note: Just because a combustion engine's fan is installed backwards, does NOT mean that the fan pushes air in the opposite direction. Either way, the fan will still suck air through the engine compartment and push air OUT ahrough the radiator.

6/30/22: I fabricated a fan that sucks in ambient air into the engine compartment. This did NOT help one bit. I also wired my A/C fan to pull hot air out of the engine compartment instead of sucking air in. This did NOT help one bit. I also pulled the inspection panels off that are located behind the tracks. This did NOT help one bit.

5/30/22: Kubota dealer said the radiator was clogged. Used the mulched the next day, the machine overheated within the same time frame. I pulled the radiator out of the machine that evening and found 1out of every 4 of the radiator fins bent over. Kubota said they cleaned the radiator and charged me $400, but they never pulled the radiator. If they did, they would have notices the bent over fins, Shamefull!. All fins were straightened and the radiator was cleaner with "New-Bite" again. Operated the next day, problem was still there.

5/21/21: As suggested by the first Kubota dealer; I transported my Skid Steer to a different Kubota dealer to see if they would have any better luck resolving this problem. no luck, the over heating problem was still there.

Update 5/18/22: The SS went back to Kubota because it's still overheating. As requested, this time I delivered it with the mulching head on it. The tech spent most of the day testing the machine. He began by rechecked the new injectors to assure that all four were running correctly. They were.
Kubota Corp thought that the DEF Re-gen system might be clogged. They forced a re-gen and confirmed that the system was running at the correct temp and was not clogged. He operated the machine with his computer hooked to the system and sitting in his lap. Any time the mulching head was running the engine coolant temp rose significantly. Shut the head off and the temp began to lower. With this, he checked the engine and exhaust temps. He noted that the all engine and exhaust temps never increased enough to affect the coolant temp. This has lead him to believe that there could be a restriction somewhere in the hydraulic system. I'll have another update as soon as I know something. Flow test preformed, hydraulics flow as supposed to.

5/12/22: Took the machine to the Kubota dealer. On 5/2/22. motor still not throwing any codes. Motor is using 1/2 quart of oil every 300 hours. Kubota mechanic says that it normal usage. Mechanic checked port after the turbo to check for "oil burn". Turbo ports are clean with no residue.
After long deliberation, Kobota decided to send the injectors out to be tested. Three injectors were pushing too much diesel and failed the POP test.. Kubota warrantied all 4 injectors (zero cost for the repair).
***Mulched with the machine today: After 1/2 hour mulching, the machine is still overheating. Called
Kubota dealer, they said; tomorrow (5/13/22) they are going to set a conference call with Kubota to discuss the problem.

5/22/22: Kubota suggested setting the high flow settings from right side 14 left side 9 to 12-8 respectively. Machine still overheated.

5/12/22: To eliminate the hydraulic system as the problem. I jumped the fans in the Loftness hydraulic cooler that is mounted on the top of the machine. When the fans are on (all the time), the hydraulic system is running at 125 degrees, and the motor still gets hot.

Update: 4/25/22: Changed the thermostat and both belts. Machine continues to run hot while running the mulcher. The longer I use the machine the hotter it gets.



Thanks for your help
Mike