JD 2650 Overheating

[Roy_H]

Things have improved a little bit but the tractor wasn't under much of a load. The gauge is now hovering in the red/green area. The top hose is running hot and the bottom hose is running cold.

That sounds like a circulation problem so it's thermostat , pump or blocked rad?

 

[Ley253]

Machine of that age, I would be thinking of internally choked rad. Get it hot and then check for cold spots in the core.

 

[sh40]

Run it hard without the thermostat and see how she fairs. I'd rather be running it fulltime without the thermostat than running with a thermostat in the red zone.

 

[Ley253]

Be careful if running without the stat. Some engines rely on it to direct coolant flow, and will be damaged if removed. Leyland 4.98 is an example. Without stat, coolant just circulates in the block, bypassing the rad.

 

[Happy hillbily]

I would be inclined to remove the rad off the tractor, and give it a really damn good clean, inside and out. I had a similar problem with a ford 4600. Thinking it was the head gasket, i removed the head only to find the gasket was in perfect order, as the tractor had done 15k hrs + i sent the head off to be refurbished as the valve guides were extremely worn, whilst the head was away i thought i might as well take the rad off and give it a thorough clean with the pressure washer, although it looked quite clean on the tractor, it took over an hour of washing with the pressure washer to get it clean, its been perfect since.

 

[Roy_H]

I would be inclined to remove the rad off the tractor, and give it a really damn good clean, inside and out. I had a similar problem with a ford 4600. Thinking it was the head gasket, i removed the head only to find the gasket was in perfect order, as the tractor had done 15k hrs + i sent the head off to be refurbished as the valve guides were extremely worn, whilst the head was away i thought i might as well take the rad off and give it a thorough clean with the pressure washer, although it looked quite clean on the tractor, it took over an hour of washing with the pressure washer to get it clean, its been perfect since.

I suppose you could pressure wash the rad without actually removing it? ( Been there done that )

 

[Happy hillbily]

You need the nozzle square on to the fins to avoid damaging them.
With the john deere having a fuel tank in the nose cone, and the engine behind, its simply not possible to do the job properly without taking the rad out.

 

[jd6420s]

Again thank you for all the replies. I have had the radiator out and given it a good clean but there wasn't really anything wrong with it. I've flushed water through the inside and there aren't any problems there. The thermostat has been changed but there isn't any difference and it is still going into the red. The top hose gets hot but the bottom hose is very cold. I can only think that it must be the water pump.

 

[celtis man]

We had similar symptoms with our Nh combine, but our one was into blowing off the top radiator pipe.
So we had the cylinder head off new gaskets, new water pump and fitted a better radiator.
Cured it [emoji3]

 

[Right-arm fast]

Again thank you for all the replies. I have had the radiator out and given it a good clean but there wasn't really anything wrong with it. I've flushed water through the inside and there aren't any problems there. The thermostat has been changed but there isn't any difference and it is still going into the red. The top hose gets hot but the bottom hose is very cold. I can only think that it must be the water pump.

I would change the water pump anyway if you take it off to have a look. I don't know if it will have a plastic impellor but if it has it wont be worth keeping anyway. I would have thought a tractor of that age would be cast or steel but I don't know. Does sound like the pump could be the culprit.

 

[marco]

i will refer you to post number 3

 

[robo]

Hello, I have a John Deere 2650 and the temperature gauge is always going into the red. It sometimes comes down to midway in the green on the gauge but most of the time stays in the red, it never boils over however. I have taken the thermostat out and put it in boiling water and it opens at 82 degrees as it should and then closes again.When I put it back in it still overheated. I am only using a haybob on the back of the tractor so it is hardly being overworked either. I did leave the thermostat out to see what happened and the temperature stayed really low and didn't get up to temperature and was only a quarter of the way into the green on the gauge.
I have made sure the fan belt is tight and the radiator is definitely clean as well.
Should I change the thermostat anyway and see what happens or could it be something else causing it to overheat? Thanks in advance.

check water pump sometimes impeller can part company with the shaft

 

[X344chap]

Check or replace the radiator cap as well. Get a cheap IR digital temperature gun and check for cold spots in the radiator core

 

[jd6420s]

I changed the radiator cap a couple of weeks ago and there was no change. The water does flow very quickly through the radiator if you put the hosepipe through it. You could be correct that there are cold spots in the radiator and it isn't working very well but when the gauge is running in the red the top hose to the radiator is hot and the bottom hose runs cold. My thinking is that if the radiator wasn't working properly, it would be running straight through and it would be coming out of the bottom hose hot as well. I'm still waiting for the pump to arrive and I am hoping it is that because I'm out of ideas if it isn't.

 

[Hesston4860s]

You sure it’s an issue and not just wiring ?, my 3050 runs fine temp half way in green. Soon as i switch the lights on it’s straight into the red !.
Fuel gauge is similar but it reads normal in low multi power but nearly full in high lol

 

[jd6420s]

The wiring can be a bit tricky and sometimes you do get movement on both of the gauges when you turn on the switch for the blower or the heater. It isn't by too much though and goes back to where it was before when I turn the switch back again. It was when I took the thermostat out and it started running in the low area of the green that suggests the flow isn't as good as it should be.

 

[jd6420s]

I've taken the water pump off today and it doesn't look too bad. It has a plastic impellor and the replacement has a steel one. It is tight on the shaft so hasn't been spinning at all. I was really hoping that there would be something more obvious. I had been running it last week without the thermostat in and the temperature gauge had been running in the low green area and the radiator had been warm. When I ran it with the thermostat in it was in the red and the top hose to the radiator was hot but the radiator was still pretty cold. Whilst it is all still in bits does anyone have any other ideas about what I can do?

 

[Macsky]

I've taken the water pump off today and it doesn't look too bad. It has a plastic impellor and the replacement has a steel one. It is tight on the shaft so hasn't been spinning at all. I was really hoping that there would be something more obvious. I had been running it last week without the thermostat in and the temperature gauge had been running in the low green area and the radiator had been warm. When I ran it with the thermostat in it was in the red and the top hose to the radiator was hot but the radiator was still pretty cold. Whilst it is all still in bits does anyone have any other ideas about what I can do?

Are you certain that the original and new thermostats are fitted the right way round? Don’t even know if it’s possible but perhaps they were upside down, and not able to open fully against the flow of coolant?

 

[jd6420s]

Hello again. I am busy putting the water pump back on this john deere 2650 tractor. Does anyone know what torque setting I should use?

 

[Courier]

I've taken the water pump off today and it doesn't look too bad. It has a plastic impellor and the replacement has a steel one. It is tight on the shaft so hasn't been spinning at all. I was really hoping that there would be something more obvious. I had been running it last week without the thermostat in and the temperature gauge had been running in the low green area and the radiator had been warm. When I ran it with the thermostat in it was in the red and the top hose to the radiator was hot but the radiator was still pretty cold. Whilst it is all still in bits does anyone have any other ideas about what I can do?

If some of the tubes have got severely blocked over time then overall cooling efficiency can be compromised without appearing to reduce the overall flow rate.
Perhaps it is time to bite the bullet and replace the radiator core ?