JD 650 Overheating - 521 hours - thermostat replace?

[Capricious]

Once the flushing is done, you might try refilling with just water and seeing if it still runs hot. If it still overheats, you haven't wasted the antifreeze.

The antifreeze/coolant DOES help the engine run a bit cooler than with just clear water, but I don't think it would make a big difference.

And if the problem IS cured, don't forget to replace the clear water with the mixture

 

[Rock knocker]

The antifreeze/coolant DOES help the engine run a bit cooler than with just clear water, but I don't think it would make a big difference.

Don't think that is true, water has a very high heat content.

Specific Heat of some common Substances

 

[Capricious]

"...Don't think that is true..."




Regardless, I would try it with clear water first. If it runs cool on water, then try the 50/50.

If it doesn't cool on clear water and/or 50/50, then it's probably time to pull the radiator for cleaning, and check the water pump for eroded/slipping impeller.

 

[Capricious]

If anyone wishes to read about the chemical properties of antifreeze, and whether or not it helps "cool" the engine, you can read a discussion here:

Antifreeze and High Temperature

None of which really helps the OP with the problem.

 

[Topher265]

Okay, so it's very easy to check if the radiator is plugged before you actually pull it. To do it properly, you need a thermometer. Preferably an infrared one for speed, but an electronic one that hooks to a multimeter is also good enough. You simply measure the temperature at regular spaces across the radiator horizontally and vertically. If you want to be super thorough, you could make a little graph and jot down the temps every couple of inches each direction. If there is a plugged section of the radiator, you'll notice a significantly cooler (lower temperature) area of the radiator. That cool section (if found) is the part of the radiator plugged and not helping to transfer heat away from the engine. As you move from the incoming hot coolant to the outgoing cooled coolant you will notice a consistent drop in temperature...that is the point of the radiator after all. What you're looking for is a big drop in temperature in one section of the radiator all of a sudden...that isn't normal.

Have you checked/replaced the radiator cap? And also, I'd suggest replacing the tube that goes from the radiator to the overflow bottle to make sure it's clear, working and can withstand the vacuum as the engine cools. I would also be suspicious of the water pump impellers as well at this point.

Great article on antifreeze Capricious. The heat exchanging ("cooling") of antifreeze mixtures perform very similarly to plain water, true. But (IMO) the point of the mixtures is to provide protection at the extreme ends of the engine temperatures (freezing/boiling) vs either pure liquid.

 

[Capricious]

"...Have you checked/replaced the radiator cap?..."



A good point.



Something I thought of last night: The OP mentioned finding a leak and replacing some hoses after the first overheating. Were there any "air bubbles" left in the system upon refilling? I would think that the air would evacuate from the cooling system on a tractor rather easily, compared to an auto with heater core and hoses and so forth, but maybe not. Having the thermostat housing apart may have introduced more air to the system.

In other words, was the OP sure that the system was totally refilled after the hoses were replaced?

 

[Edensgardener]

I never did come back here and let you all know what the issue (appeared) to be! So SORRY! Someone else may end up with the same issue and I wanted to have the final resolution here;

Well, I also picked up an air filter - at some point, and THAT did the trick!! Capricious I think you noted to change that out - and indeed it was pretty dusty with all of the dry weather we've had. It's a wonder my skin's not as soft as silk with all of the free skin exfoliations I get. LOL

Thanks again everyone - next up is a loader - but that's a different thread!

 

[Capricious]

I never did come back here and let you all know what the issue (appeared) to be! So SORRY! Someone else may end up with the same issue and I wanted to have the final resolution here;

Well, I also picked up an air filter - at some point, and THAT did the trick!! Capricious I think you noted to change that out - and indeed it was pretty dusty with all of the dry weather we've had. It's a wonder my skin's not as soft as silk with all of the free skin exfoliations I get. LOL

Thanks again everyone - next up is a loader - but that's a different thread!

I believe it was "Jerry/MT" who brought up the air filter issue.

Happy things worked out well.

 

[Edensgardener]

Ah, I guess I spoke too soon. JD overheated again the other day. So, having done every other thinkable thing, I pulled the radiator and took it in. Now they say it wasn't nearly bad enough to have given me troubles or caused any overheating, although they did paint it a pretty new coat of black paint for me.

So, the possibility exists that either 1- I had it OVER filled or 2-the pump isn't working right or 3- the new thermostat isn't working right.

I did re-check the newly installed air filter - looks ok. Minimal leakage noticed around the base of one hose where I may not have had it clamped down quite tight enough.

NOW the challenge is to GET THAT RADIATOR BACK IN! how the heck.... I know it came out of there! lol I can't seem to get the fan cover in so it's on TOP of the bottom hose outlet on the radiator. I can't slip it back out of the way far enough - and someone else was helping me get it out of there, so I didn't see exactly how he managed to slip it up past the fan cover.

It's like doing a puzzle - any tips?

 

[Capricious]

"... I had it OVER filled..."


I assume by "overheating" that you mean the warning light came on. While over-filling might cause the radiator to spit out the excess coolant I don't think it would actually cause the engine to overheat.

I would install a temperature gauge and see just how hot the thing is getting. Not unusual for sender units or wiring to temp. lights to go bad.

If it really is overheating, I would not think the new thermostat defective, as the problem pre-dated the installation of the new thermostat. (is it possible to install the thermostat upside down in this tractor?)

It has been brought up before: With the engine cool, start it up with the radiator cap off and watch for bubbles in the coolant in the radiator (bad sign).

If you suspect the pump, might be easier to replace the pump while the radiator is out.