Temperature gauge pegs out

[CMHigdon]

We have a Branson 2500. I was mowing the pasture, and the temp gauge was running in it's normal position. I glance down periodically while mowing, and I saw that it was pegged out in the red. I immediately shut everything down and moved to the shade. I checked for blockage/dust, and there was a little that I cleaned off. Went in and ate lunch to give it time to cool down. We checked the air filter, and coolant. We went ahead and replaced the air filter, because it was dirty, and it was time to replace it anyway. Started it up next day, and it stayed on cold. Started to mow and glanced down at the temp gauge, and it was pegged out on hot again. I hadn't even been mowing for 3 minutes.

Anyone else run into this?

Thanks for any help.

 

[Rebeldad1]

stuck thermostat
broken fan belt
broken water pump impeller
head gasket

 

[CMHigdon]

stuck thermostat
broken fan belt
broken water pump impeller
head gasket

Thank you.

 

[K5lwq]

Another possible issue is radiator is clogged although you stated you cleared. Sometimes it is difficult to tell. Use a flashlight and shine through the fins. If the light can not pass through it needs to be cleaned.

 

[ptsg]

I agree with K5 and I'll add, check the coolant at the radiator (with the engine cold so you don't burn yourself). Don't rely solely on the overflow tank.

If the level is below the temperature sending unit, it can give erratic readings.

Can you tell if the engine is actually overheating? Could also be a bad sending unit or just the connection. Or even the plug on the back of the dashboard.

 

[dirttoys]

stuck thermostat
broken fan belt
broken water pump impeller
head gasket

That is a pretty good list, have we checked coolant level?

 

[/pine]

A faulty sending unit is easy to check...and a likely suspect...!

 

[CMHigdon]

Thanks for the replies. We brought it to the house, cleaned the radiator again with air - a little dust blew out. Flushed/changed coolant just to see what it looked like - it was very clean. Started it up, and the gauge rode at cool for a few minutes. Then the needle jumped to hot. It went back and forth with no pattern. Radiator/hose cool to the touch. It went back to cool and rose slowly (as normal), and radiator/hose getting warmer for several minutes, then jumped to hot. Doesn't seem to be any trigger for the jump.

 

[K5lwq]

Sounds like a faulty connection or bad sensor to me.

 

[CMHigdon]

That is a pretty good list, have we checked coolant level?

It was good, but we went ahead and drained/flushed/replaced it. It looked fine.

 

[dirttoys]

It was good, but we went ahead and drained/flushed/replaced it. It looked fine.

Yup saw your reply. Sure sounds like a bad sensor (you are blessed). Just for fun, might check the radiator for exhaust/bubbles.

Best,

ed

 

[CMHigdon]

And it probably doesn't matter that the Branson is a 2800... I had the Kubota (L)2500 on my mind when I wrote the first post.

 

[fatjay]

I recently had mine peg and it was a combination of thermostat stuck closed(never seen that before) and the hydraulic oil filter clogged creating additional load on hte pump. Replacing one helped, replacing both solved it. Any time I have any sort of issue like this, I replace every single consumable part to the tune of a few hundred dollars, but it saves the equipment which rings in at a few thousand dollars.

 

[Fixastuff]

Could also be the instrument cluster going bad. If you disconnect the temp sensor wire from the sender unit and ground it to the engine, this should make the cluster read max hot and the wire disconnected it should read max cold.

 

[denjen]

Just as an FYI, I had the opposite problem, mine (3515 CH) was always cold and one time it did register normal range. It turned out to be a combo of thermostat and temp gauge which is part of the instrument cluster and is replaced as a whole. If you replace instrument cluster remember the hours. We did test the sensors; but they were fine.

 

[Muddy Jim]

I suggest you not get too worried about all the cooling components until you have cleaned and re-tightened the ground and sensor lead connections at the temp meter and temp sensor. I have a truck with a bad ground point deep in the dash where I cannot go to repair it, and the temp sensor periodically pegs on maximum and then returns to normal when it feels like it.
Even though I know all about the defect, when I glance down and see that high temp needle way up at the top, my stomach jumps anyway.

 

[marhar]

Another possible issue is radiator is clogged although you stated you cleared. Sometimes it is difficult to tell. Use a flashlight and shine through the fins. If the light can not pass through it needs to be cleaned.

Try a radiator flush from an automotive parts store. Make sure no pets are around as they are attracted to the antifreeze and it is poisonous.

 

[CoyPatton]

Not sure on your Branson, but many temp sending units, go full hot on the wire being grounded out. Cutting tall brush has always been know for finding lose hanging wires and hoses and reeking havoc with them. You may want to add a close underneath inspection of the tractor to regular cleaning of the radiator fins. A few years back there was a product called Radiator Genie for clean out the fins. I have not looked for it in years however.

 

[lpakiz]

First I would suspect a plugged up radiator. Like another poser suggested, put a bright light in behind the radiator, by the fan blades. Then look thru from the the front. You should see light.

Another basic cause is fan belt slippage. At WIDE OPEN throttle, standing still, the fan should “buzz” and you should hear air “roar”.
If you can, try to turn the fan hub (or even the alternator pulley with a wrench or socket) to see how much effort it takes to make the belt slip. Even a tight belt can slip if it’s glazed enough.

 

[Cougsfan]

I have had two problems similar to yours. First, Mine used to overheat while mowing or going up steep hills. I cleaned the radiator with air and water several times but it didn't seem to help. It is difficult to clean it with all the shrouds on the backside and oil cooler on the front. Finally I removed the radiator and boy was it clogged with debris from mowing! I carefully cleaned it with a pressure washer and it works fine now. Second, Several of my gages give weird readings occasionally (Fuel gage reads way past full or empty, the temp gauge does the same, and my tach may register rpms X 2) This just happens now and then for a short while. I am assuming I have a bad connection on one of the plugs under the dash, bit have never gotten around to tearing apart and adding dielectric paste to the connectors, which I am hoping would correct it.