Tractor "almost" running hot

[belah]

Hello friends on TBN. I have a question. I have a 1992 Kubota M4030SU that has never caused me any problems until this year. while bush hogging with a 6ft Woods cutter, the temp guage goes "almost" to Hot after about 11/2 hours of cutting. It never gets all the way to hot and never boils over even if I use it all day. I have flushed the radiator and replaced with new coolant. I have cleaned the radiator fins with a water sprayer and I have checked the air filter which was OK. I have changed oil and filter.

I have noticed whenever it gets near the hot zone on the guage, the engine idles rough. I don't know if this has anything to do with it or not but it idles normally whenever the engine is cool.

Does anyone out there know what is causing my problem? Would you please give me some advice? Thank You in Advance !!!!!

 

[RoyJackson]

Have you replaced your thermostat?

 

[TripleR]

Have you replaced your thermostat?

+1, might also see if you can borrow an IR heat sensor to verify temp.

 

[belah]

Thank You so much for your replies. I had thought about maybe the thermostat might no be opening all the way due to rust or other gunk but I didn't know if this was something that might happen. I am definately going to check the thermostat. What do you think is making it idle rough when it's hot?? Thanks again!!!!:thumbsup:

 

[TripleR]

I have pretty much exhausted my mechanical knowledge on diesels, maybe Roy, Spyderlik, Leonz or one of the more mechanically inclined can help you out, about now is when I would be calling the service truck if the thermostat didn't do it.

 

[bigbull338]

ok youve washed your rad off an flushed it out,an you still have the prob.have you cleaned/changed your air filter.it really sounds like you need a new thermastat.

 

[RoyJackson]

That rough running might be due to the engine running hot, or might be something else.
However, try one fix at a time (if feasible)...so, let's see what the thermostat does.
BTW, can't say I've ever had this with a tractor, but in a car or truck, when coolant hoses get tired, they can collapse (restricting flow). It takes educated finger, but squeeze your coolant hoses (when the engine is NOT running!!). I don't think you should be able to squeeze them much.

Just as a reminder, do not shut down a hot engine. Let it run at idle for a few minutes.

I have pretty much exhausted my mechanical knowledge on diesels, maybe Roy, Spyderlik, Leonz or one of the more mechanically inclined can help you out, about now is when I would be calling the service truck if the thermostat didn't do it.

I dunno about Spyder or Leonz, but I'm not too mechanically inclined...but I did stay at a Holiday Inn last night (wife locked me out when I came home sh*tfaced)

 

[dex3361]

While you are looking. With the engine cool drain down enough coolant to see if your radiator passages are clean i have had this issue with a radiator that is plugging off on the inside. I have had luck with the prestone superflush. It could be the water pump not working as well. With the engine cool and the cap off run the engine and let it warm up till the thermostat opens then see if you have good circulation. :thumbsup:

 

[Jerry/MT]

Hello friends on TBN. I have a question. I have a 1992 Kubota M4030SU that has never caused me any problems until this year. while bush hogging with a 6ft Woods cutter, the temp guage goes "almost" to Hot after about 11/2 hours of cutting. It never gets all the way to hot and never boils over even if I use it all day. I have flushed the radiator and replaced with new coolant. I have cleaned the radiator fins with a water sprayer and I have checked the air filter which was OK. I have changed oil and filter.

I have noticed whenever it gets near the hot zone on the guage, the engine idles rough. I don't know if this has anything to do with it or not but it idles normally whenever the engine is cool.

Does anyone out there know what is causing my problem? Would you please give me some advice? Thank You in Advance !!!!!

Here's some possibilities:

loose fan belt, stuck or malfunctioning thermostat, clogged air filter, clogged air side of radiator, faulty temperature gauge, lower hose collapsing at high rpm,clogged coolant side of radiator, leaking fuel injectors.

I've put them in the order of what I believe is decreasing probability.

 

[grsthegreat]

my old JD did that to me...turned out the fins in the radiator were packed with crap. I blew out everrthing with the air gun...problem solved.

just looking at it didnt help. i had to remove front grill and look straight into the radiator. it was packed

 

[Don87]

my old JD did that to me...turned out the fins in the radiator were packed with crap. I blew out everrthing with the air gun...problem solved.

just looking at it didnt help. i had to remove front grill and look straight into the radiator. it was packed

And just to add to this point...........

Sometimes a pressure washer, or the air gun can be deceiving..........they can actually 'bend' the fins over, thus blocking air flow through the cooling fins. Double check after using either tool, and be careful while using them ( basically straight on towards the fins, never on an angle).

 

[grsthegreat]

And just to add to this point...........

Sometimes a pressure washer, or the air gun can be deceiving..........they can actually 'bend' the fins over, thus blocking air flow through the cooling fins. Double check after using either tool, and be careful while using them ( basically straight on towards the fins, never on an angle).

good point.......thats why i didnt want to use my pressure washer

 

[Don87]

good point.......thats why i didnt want to use my pressure washer

They can be used, but ya gotta be very careful.

BTW...........Veteran member at 1,000:thumbsup:

 

[grsthegreat]

They can be used, but ya gotta be very careful.

BTW...........Veteran member at 1,000:thumbsup:

ohoh..now ill have to think of a few more things to say.....almost a vetern member

 

[grsthegreat]

They can be used, but ya gotta be very careful.

BTW...........Veteran member at 1,000:thumbsup:

oh well....ive got to hit the sack...i guess ill have to leave it at 999 for today :laughing: :licking:

 

[MikeInEburg]

If you mow a lot, I think the radiator fins are not as clear as you think. I had the same thing happen. Ended up removing the radiator from the tractor and REALLY cleaning the fins with a garden hose. While at it, replaced the upper and lower hoses and thermostat. Problem solved.
Mike

 

[Rhinorider]

I do alot of off roading in my Yamaha Rhino. Going through deep mud holes and places I shouldn't the radiator often gets plugged with mud and overheats. I made a niffty wash out tool, take a long soft copper drop tube like one for a bathroom faucet, cut the musroom end off and get a compression fitting that screws on the end of a garden hose. On the other end smash the end of to tube closed, then drill a series of 1/16 or 3/32 holes in a straight line in the side of the tube, about 8 to 10 holes. Hookit up to garden hose and slide it in behind radiator. Works like a charm and doesn't have enough pressure to bend the fins. You will be amazed at the gunk that washes out.

 

[deepNdirt]

while Bush hogging and dust/grasses flying around My first thought were to have a possible clogged radiator, surely Has happen with most of us before,
You seem to have taken the appropriate steps to troubleshoot this issue, cleaning and flushing the radiator would have been my first thought,
although I haven't read any suggestions of possible water pump problems,
It does sound to me like a water circulation problem, while the tractor is cold and first started with the radiator cap removed, keep the tractor at a high idle,Note: careful to stay clear of the fan, after a few minutes the water should warm the T-state opens and you'll Begin to see water movement through the filler hole, good sign that the pump is working:thumbsup: although not always can you see the water movement, kinda have to have a trained eye for this, and again as mentioned if the T-stat is stuck closed it will also not allow the water to circulate,..........

Shade-tree trouble-shooting

Try doing this with the radiator, if you have a size pc. of cardboard equivalent to the size of radiator, while tractor is ruining see if the cardboard will be pulled and held in place to the radiator, if there are no radiator obstructions it should stick to the radiator by suction,
Meaning the rad is clear .... cannot use paper as it is too lightweight and probably stick with a minimum suction,...
this will give you an assurances that the water is being cooled by the Rad.
and you'll know to move on to something else as being the problem,

 

[Dead Horse]

my old JD did that to me...turned out the fins in the radiator were packed with crap. I blew out everrthing with the air gun...problem solved.

just looking at it didnt help. i had to remove front grill and look straight into the radiator. it was packed

Agreed.. it can take a LOT of time, water and effort to get the fins clean.... just spraying the rad can actually make it worse as the caked on dirt and stuff will turn to near concrete if you do not get it all out.

I use a combination of hose water pressure and compressed air on both of my tractors and I am often astounded how much crap is lodged between the fins.

I spray a LOT of water in the rad while the engine is running such that the water is hot and it actually cleans better..... I do a check test with compressed air and a 1/4 tube about 18 inches long and with a 90 degree bend on the end of it attached to the air chuck, so I can blow compressed air right at the fins. Do the WHOLE radiator........especially the corners.

Like I said I am astounded how much stuff gets in there, and my work conditions are not that dusty.......

 

[belah]

You all are going to have to excuse my IGNORANCE but I just happened to find a very loose fan belt on my tractor(I can almost swear that I checked it earlier). Could this be the problem with it "almost running hot" esp. at high RPM's and under heavy work?? I have now done everything else that you all suggested but change the thermostat but today is Sunday and the part's house is closed. THANK EVERYONE who sent these great replies!!
If you don't think this loose belt could be the problem, please let me know.:ashamed: