My 2008 BX 2350D has been running hot!

[Merlin]

While cutting grass my temperature gauge always used to run at 50%-60% @ 90F outside most of the time.(Year 2008 with 2980 hours) Now it has been running at 90% all of the time and will go into the red if I don't slow my rpms down below 2500 . I always clean the filter screen and blow the radiator with air. Everything I have done recently to fix the problem has been to rebuild the HST shaft bearings, rebuild the 60" belly mower deck, took the radiator out and washed with radiator cleaner, changed thermostat, new upper and lower radiator hoses, cleaned fan blades, new water pump and belt. 50/50 antifreeze. Still runs 90%. What more can I do? It runs and starts perfect! Any ideas welcome...

 

[GreensvilleJay]

Any chance the plastic cap on the overflow bottle ,vent hole tube to rad cap is plugged ? My 2019 BX23S had a recall, Kubota sent out a new cap . The deal is if it gets plugged overflow rad water never gets back into the rad. Engine overheats,poof....This is a LOT easier to show than describe..
hmm.. easier way to say it... is the LEVEL of the water in the proper range ?midway ??

 

[07wingnut]

When it consistently overheats, no matter what you do, it is time to suspect the temperature gauge itself or the sender. Find an alternate way to measure the temperature, and if that shows a good reading, its time to test the gauge, and the sender.

 

[Henro]

When it consistently overheats, no matter what you do, it is time to suspect the temperature gauge itself or the sender. Find an alternate way to measure the temperature, and if that shows a good reading, its time to test the gauge, and the sender.

Just a crazy thing to add to what has been stated above, but in the event your engine overheats, this will be obvious with steam appearing under the hood. Shut down immediately, and let the engine cool down before adding any coolant, and worrying about what the real cause is.

People have reported adding cold liquid to over heated engines soon after shutdown while they are still hot, with really bad results.

You may already know this, but some do not.

Just a bit of advice, just in case...

 

[RCW]

When it consistently overheats, no matter what you do, it is time to suspect the temperature gauge itself or the sender. Find an alternate way to measure the temperature, and if that shows a good reading, its time to test the gauge, and the sender.

Bingo…..first place to start. Get a laser infrared thermometer and check top and bottom of radiator.

My BX2360 has spiked to HOT HOT within 5 minutes’ run time before. Engine wasn’t even to operating temperature yet.

Just cleaning the spade connection on the sending unit has worked so far.

BX RUNNING HOT...Or Not?

Comes up often, and often they can run hot. Usually gummed up radiator. Started mowing other night and within ten minutes I see this: Holy smokes!! (Not what I really thought)!! But wait a minute...haven’t run long.... Shut her down. Get laser thermometer. Top radiator hose is 135F...

www.orangetractortalks.com

Now, yours may be running hot. Just suggesting you rule something like this out before going too far into it. Sounds like you’ve already done a lot of preventive maintenance already.

 

[Merlin]

Any chance the plastic cap on the overflow bottle ,vent hole tube to rad cap is plugged ? My 2019 BX23S had a recall, Kubota sent out a new cap . The deal is if it gets plugged overflow rad water never gets back into the rad. Engine overheats,poof....This is a LOT easier to show than describe..
hmm.. easier way to say it... is the LEVEL of the water in the proper range ?midway ??

 

[Merlin]

I checked the vent hole cap. It was clear. But it looks like the straw that goes into the bottom is missing. Thanks for bringing it to my attention.

 

[lugbolt]

with a cold engine remove the radiator cap, then start engine. U see any bubbles in the coolant? If you do, you have either a leaking head gasket or cracked head. Or both.

have seen one water pump impeller come loose from the pump shaft once. Lots of loose belts too.

On BX's because the motor is installed backwards, look at how air has to flow. It flows IN from the footwell area (by the battery), pulled through the radiator, and out the front through the lower hood. If there is any restriction at all in any of those areas, it's gonna contribute to overheating.

 

[whitetiger]

It was clear. But it looks like the straw that goes into the bottom is missing. Thanks for bringing it to my attention

There is no straw from the cap into the tank. It has a hose from the bottom of the tank to the fill neck of the radiator.

 

[Nicksacco]

You obviously take good care of your tractor.
I would also recommend checking the temp with an infrared sensor or similar before ripping things apart.
Only other things I can think of is the fan belt slipping or something wrong with the water pump.

 

[GreensvilleJay]

That white 'overflow' tank is supposed to be 1/2 full of coolant when engine is cold. In the recall papers.. K says when cap open, real hot coolant flows into the overflow tank, when the engine/rad cap cols down, it'l suck the overflow coolant back into the rad. if for any reason it can't, then over enough time, you'll pump all the coolant out ot the engine ! Oospy... overheated engine , $$$$$$$$$ You probably won't notice the loss of coolant as it drips onto ground,or evaporates over time.
or sure, remove rad cap when cold, look inside to see level of coolant, and if overflow tank is low, refill with 50/50mix with rad cap off. Close cap, run tractor for say 15 minutes(till normal running temp), look at overflow tank, check the level.
Just thought... check the hose between rad cap and tank. it has to be 100% sealed . If not sealed then coolant pisses onto ground drirectly from rad cap and tank will be empty.