JD 4310 Overheating

[Westonium]

My tractor dash temperature gauge keeps climbing up to the red, and beyond (!)

What I've tried so far:

1. Replaced the oil (no milkshake, no glitter), it was due but not way overdue. Replaced the radiator fluid, it was due. Probably overdue. From a cold morning start on new fluids, it gets to red from a fast idle in roughly 10 minutes.


2. Replaced the thermostat. Again, from a cold start, it gets to red, no change.


3. Removed the thermostat entirely. Topped off the fluid (50/50 Prestone pre-mix), and again it gets to red in about 10 minutes. This time, wholly unconvinced that it was really that hot, I took the cap off to test the temperature. Only a little pressure, and the fluid is only showing 99 degrees.


What next? I am preparing to replace the water pump...
It seems to run just as always,

Ideas?

 

[sisupower]

Got a temp gun? When it's showing hot and running point temp gun at block by thermostat and see what it says. If it's not to extreme you might have a bad gauge or temp sensor bad

 

[Westonium]

I do have one - I will give it another try and post the results shortly.

 

[Wagtail]

Seeing as you've got a temp gun, how are the temperatures of your supply & return lines of your cooling system?

When you replaced the radiator fluid did all of it come out (within reason, of course) and at a fairly steady flow? When you re-filled the coolant, did you put in less than you thought you would?

 

[Westonium]

117 F is the hottest I can get the thing to read, pointed at the block where the sensor goes it. The temp needle was pegged after driving the thing down and back the hilly driveway (800 feet of it). Seems like the sensor is off... The top of the radiator is only 100F.

 

[sisupower]

Yea your not over heating. Electrical issue of some sort

 

[BrokeFarmerJohn]

My 4320 does not show temperatures on the temp gauge, I just have green and red areas. So idk what the actual temp ranges are.

Only things it could be is coolant fluid, water pump or Tstat. The Tstat is the most likely culprit but you changed that.

I would agree about pointing fingers at the water jacket thermometer and gauge.

I would call the JD dealer, ask to speak to a mechanic and ask them how to test them, most likely the thermometer is faulty.

 

[RoyJackson]

I'm also of the opinion the gage is bad.
I've owned three Deere with Yanmar engines...and all have tended to run cool (as long as the radiator screens are clean)

 

[sisupower]

I'll tell you how to check temp sensor. Unplug the white wire on sensor. Get a multimeter and put it on ohms. Put one lead on terminal that you took wire off of and other on sensor body. Do it while your engine is warm not cold. And see what it ohms out. Spec should be 40-700 ohms I believe. Might have to scratch paint a bit on body to get good reading.

 

[Westonium]

Thanks for the responses from everyone above! I will test the sensor resistance today. I was trying to get ahead of the game, and I already have a lovely water pump sitting in a box in the kitchen.

I'll tell you how to check temp sensor. Unplug the white wire on sensor. Get a multimeter and put it on ohms. Put one lead on terminal that you took wire off of and other on sensor body. Do it while your engine is warm not cold. And see what it ohms out. Spec should be 40-700 ohms I believe. Might have to scratch paint a bit on body to get good reading.

It would be good to know that the gauge is going to tell me when the system is about to actually overheat .