JD 5105 overheating -- again... need some help..

[jbwrangler]

My 2000 JD 5105 (45 hp) had an over heating issue almost exactly a year ago. I flushed and replaced the thermostat and all seemed good. A few days ago I was bush hogging and saw the temp gauge in the red. I shut down and got it back to the shed the next day and blew out the radiator. Tried and again and same thing, temp goes to red. BTW, there is no boiling over or overflow out of the overflow tube.

So, being that I had just replaced the thermostat last year, I decide to try replacing the sending unit since it was easy to change and only $30. Again temp goes to red. Today I changed the thermostat, just to eliminate that. I started the tractor and set is at about 1800 RPM. With the Radiator cap off, I could see the coolant, but could not see it moving and no bubbles. Should I be able to see it moving? After about 12-15 min the needle was in the middle, then it suddenly jumped to red, then back down to the middle for a minute, then went back up to red. I had a thermometer in the radiator fill and it was at about 160. Also, the upper radiator hose is hot and the lower is cool to the touch if that means anything.

Here is what I am down to: 1. Water Pump, 2. clogged Radiator, 3. gauge/electrical issue, 4. long shot (hopefully) head gasket (I have not seen any coolant in oil or vice versa)

Is there a way to test the issues above? (When I unhook the gauge it goes to cold and when I ground it it goes hot.)

sorry for the long post and Thanks

 

[LittleBill21]

you should be able to squeeze the hoses and feel the coolant surging in it. you may want to invest in a ir temp gun. it would save you money with throwing parts at it guessing, sounds like the pump is done.

 

[jbwrangler]

you should be able to squeeze the hoses and feel the coolant surging in it. you may want to invest in a ir temp gun. it would save you money with throwing parts at it guessing, sounds like the pump is done.

Where do you take the readings with the ir gun?

 

[whis]

check water pump for play, have radiator rodded out

 

[jbwrangler]

Update... not really a conclusion though...

I had an idea last night, so I went and tried it today. I attached the old the sending unit (that I presume is good because the new one performs exactly the same) and connected it to the sending unit wire on the tractor with about a 5' wire. I then hung the sending unit in a pot of water on a propane burner where the and tip was in the water. The gauge rose slowly as the temp increased and stayed at about 3/4 to red when the water was boiling. However, when I gave the cluster a little shake (like to simulate the vibration when the tractor is running and the gauge immediately jumped to red.

I pulled the unit out of the water and let the water cool to about 150 degrees, then repeated the test. This time it did the same thing, except it went to red even before the water boiled (about 180-190)

I'm pretty sure it is the gauge/cluster at this point, although it could be the wire from sending unit to cluster.

I did have some dust inside the cluster when the over heat issue started. I removed the cluster and a couple of the rubber dust plugs on the back of the cluster were missing. I have the cluster apart now and I may try blowing that out before I do anything else.

 

[JD5210]

While I do not know if you are on the correct path to solving your issue, but letç—´ rule out that it is the engine. Connect an ohm meter to the temperature sensor, below are the ohm readings and associated temperature reading. These were taken from the 5105 tech manual. Maybe someone can tell you what the normal operating temperature is of the 3029D.

You can also take some resistors and bench test the cluster.

60 C (140 F) 134 + or - 13.5 ohms
90 C (194 F) 51.2 + or - 4.3 ohms
100 C (212 F) 38.5 + or - 3.0 ohms

Take care in putting the instrument panel back in so as not to break the windowpane, the attachment is from a 5210 on order to tighten screws, do not know it will work for you.

 

[jbwrangler]

While I do not know if you are on the correct path to solving your issue, but letç—´ rule out that it is the engine. Connect an ohm meter to the temperature sensor, below are the ohm readings and associated temperature reading. These were taken from the 5105 tech manual. Maybe someone can tell you what the normal operating temperature is of the 3029D.

You can also take some resistors and bench test the cluster.

60 C (140 F) 134 + or - 13.5 ohms
90 C (194 F) 51.2 + or - 4.3 ohms
100 C (212 F) 38.5 + or - 3.0 ohms

Take care in putting the instrument panel back in so as not to break the windowpane, the attachment is from a 5210 on order to tighten screws, do not know it will work for you.

Thanks 5210. I found that PDF in another post you made (I think it was you). Can you tell me a little more about how to test the cluster with resistors?

 

[JD5210]

Find yourself the 3 resistors sizes from old electronics you may have laying around or try Radio Shack. There are a number of charts on the net that show you the color bands to determine resistor size. With the cluster off the tractor determine, which pin is power (red), ground (black) and sender (white) wire. For a power source you can use a battery or a battery charger. Connect one end of the resistor to the white wire and the other end to ground.

This way might be easier, the cluster is on the tractor, connect one end of the resistor to the white wire and the other end to ground/frame.

 

[Kubota 2350]

My 2000 JD 5105 (45 hp) had an over heating issue almost exactly a year ago. I flushed and replaced the thermostat and all seemed good. A few days ago I was bush hogging and saw the temp gauge in the red. I shut down and got it back to the shed the next day and blew out the radiator. Tried and again and same thing, temp goes to red. BTW, there is no boiling over or overflow out of the overflow tube.

So, being that I had just replaced the thermostat last year, I decide to try replacing the sending unit since it was easy to change and only $30. Again temp goes to red. Today I changed the thermostat, just to eliminate that. I started the tractor and set is at about 1800 RPM. With the Radiator cap off, I could see the coolant, but could not see it moving and no bubbles. Should I be able to see it moving? After about 12-15 min the needle was in the middle, then it suddenly jumped to red, then back down to the middle for a minute, then went back up to red. I had a thermometer in the radiator fill and it was at about 160. Also, the upper radiator hose is hot and the lower is cool to the touch if that means anything.

Here is what I am down to: 1. Water Pump, 2. clogged Radiator, 3. gauge/electrical issue, 4. long shot (hopefully) head gasket (I have not seen any coolant in oil or vice versa)

Is there a way to test the issues above? (When I unhook the gauge it goes to cold and when I ground it it goes hot.)

sorry for the long post and Thanks

Classic sign of a blown head gasket.
Do a leak down test.

 

[kthompson]

I have been laughed at for this but do not miss checking the air intake system. A restriction there will also overheat it. It would be next of such in there that moves at certain air flow but could just be the trash from mowing. kt