Lx865 running 255

So I've been noticing mu machine getting pretty hott.. running today i got up to 255 within 30 minutes. Changed thermostat with oem, new gasket, no leaks, with same results. waterpump 2 years ago. I took the thermostat out completely and it's still saying 255 when running full power. Any help ? Running 50/50 antifreeze...

My radiator looks bad.

Fins and all are clean free from dust and leaves.

I ran it hard for 30 minutes and it didn't stop. I'm a little confused.

TIA!!!

A few questions come to mind and maybe you already know or have done some of this.
- Did you check how dirty the fins of the radiator AND the oil cooler are AND the space between the two? From the outside in, there is the radiator, then a space, then the oil cooler, and finally the fan. The fan pushes air from the inside out and I have seen oil coolers get plugged up from the fan side with gunk and debris. Also, the gap between the radiator and the oil cooler will gather debris and block air flow. You can check it by pulling the two levers on the side of the radiator upwards & backwards. This will move the radiator back 3 inches or so so you can see between the two.
- With the fan pushing air outwards, the air inlet screen on top of the engine has to be clean.
- Radiator hoses are no kinked or pinched off anywhere?
- Fan belt is on and in good working condition?
- Is the engine/radiator actually getting that hot? Bad sensor? Check with a temp gun?
- Little more off the wall: the engine sounds normal not laboring like something in the hydraulic system is activated and going over pressure relief?
- Running engine at high enough RPM so it and hydraulics are not laboring and fan speed is higher to create more cooling?

Reminder: don't blow water or air across the fins up/down or sideways with any significant pressure. It will lay the fins over and block the air flow.

I have slid the radiator out and cleaned leaves out and sprayed out. Maybe not good enough.

Ibhave not checked with an ir temp gun. Where to check and what to look for?

I have the side panels on but the top screen is off.

If i idle up it actually gets hotter.

Air filter is new.

Belt should be fine.

Check the fan side of the oil cooler.
Further thought, if it actually is hot and circulating water it should be boiling out the relief cap. So, if not, check temp of block with temp gun (maybe near where the temp sensor is) and the radiator to verify water is circulating. Depending on readings, you may be able to prove a bad sensor, wire, or EIC board.

Im going to run get a ir gun in the morning. So I just ran it full throttle and within 10 minutes it was saying 255. Taking the cap off whole running and the dash reading 255 there was no eruption or much vapor. Added little more coolant. It's bouncing out the top but... I just thinking I may have put the thermostat in backwards so i inserted the spring side into the thermostat housing not into the block. Is that right or backwards.. spring side goes in the block correct not into the housing

Aaahhhhhaaaa! Yea, I think you're correct the spring towards the engine. A quick googling and the internet agrees also. You can probably save the money for the temp gun (unless you now just want one because they're cool). Good job on figuring it out.

Welll. I haven't figured it out yet. I stayed up till 2am tearing down and putting back. Ran machine about 10 minutes and temps running 255. The coolant doesn't seem to be circulating. I bought a temp gun today. Radiator is hott on top cool on the bottom.

Also had a flat. Got the machine on level fround and found my rear wheel is sliding bavk and forth. I'm busoomg I have a really bad bearing.

Hot top & cool bottom sounds normal and indicates at least some circulation. Is the engine block actually hot? Maybe check near temp sensor or near top hose exit.

Wheel sliding--in & out would be snap ring off the inside; forward & backward or up & down is bearings--would require bearings and seal(s). Don't keep running it. It will ruin the castings & shaft. If you're mechanical and want to rebuild the axle(s) (check the others) yourself I can give you the bearing manufacturer's numbers and maybe the seal too. I buy them off the internet and save money.

Yes, sir, it is sliding in and out the up and down and back and forth is fine. I called my local new hauling dealer. They want three hundred and nine dollars per wheel 4 the Rebuild kit. Grease is coming out the casting around the rear of the hub. The chain and sprocket look brand new

If it's in-out it may be just the snap ring broke and you may need some new/additional shims (items 22, 24, or 25). The snap ring (item 23) takes a pretty good set of pliers to handle it. You can get those NH part numbers here:


If you want to do the bearings and seals, here are the numbers for items 20, 21, and 19. If you hunt the internet you'll find them cheaper (I used to get the bearings from Autoplicity). The outer seal 27 and wear ring 17 is NH specific numbers. Either get them from NH or google the numbers and you'll find other, cheaper sources.


This is using the normal seal. I didn't find the heavy duty seal to be worth the extra cost/effort for me. It replaces the outer seal and wear ring and you pack the outer wheel bearing with wheel bearing grease and no longer use the grease zerk.

Back to the overheating issue ...
Back when I was being "trained", the instructor said a difference of 10 degrees F was what to expect, any more than that indicated a plugged radiator.
( beware, I have almost no "real world experience" here, my shop was almost exclusively dyno run & cooling tower.)