YM3110D Overheating - Time for new radiator?

[normde2001]

Before you buy a new radiator try a correct back-flush. Disconnect the upper hose at the radiator, remove the rad cap, stuff a garden hose into the upper hose and seal with rags, cover electricals with plastic, turn on water, gradually increasing pressure. Run full pressure until water runs clear out radiator top. I have a 4' hose extension I use on my nozzle for this. Again, be absolutely sure fins are clear. Shine a light through the radiator. You should run about 160* max

 

[coosa]

I have posted here before about my 2210d that runs hotter than I think it should when running a bush hog. It sounds like you could benefit from rodding out your radiator, but I don't think it would help me. Mine is a Fredrick's tractor and the radiator is nearly new. They replaced the radiator, water pump, and thermostat when they redid the tractor.

The temp gauge will stay on the center mark for the first hour or so of work, but then it gradually moves towards the 3/4 mark if I keep working. I've used a laser thermometer to check the temp at the top of the radiator where the coolant enters, and the center mark is 160 degrees, while the 3/4 mark is 190. I think that is hotter than it should run; is it?

My neighbor suggested I mount a fan to blow on the radiator and cool it down, so I found an 8" fan made for that purpose and tried it. It didn't help a bit. I think the radiator is just not big enough for the tractor. Good luck with yours.

 

[winston1]

I agree with coosa and believe some of the old YM models had just enough cooling and nothing extra. Too many times I have read of head gasket problems and I venture to say most were caused by overheating. No doubt poorly maintained cooling systems were a part of the problem. However, I have owned several different tractors in my lifetime and none had cooling problems other than the 2002D Yanmar. Just an opinion so go ahead a attack.

 

[rScotty]

I agree with coosa and believe some of the old YM models had just enough cooling and nothing extra. Too many times I have read of head gasket problems and I venture to say most were caused by overheating. No doubt poorly maintained cooling systems were a part of the problem. However, I have owned several different tractors in my lifetime and none had cooling problems other than the 2002D Yanmar. Just an opinion so go ahead a attack.

Yes, cooling was a problem with several old YM models. It was barely adequate in spite of the pretty good hi-copper brass that they used to make the radiator Yanmar published several technical bulletins on this. There were two fixes:

One problem was that on some models the shroud around the fan was not air-tight enough against the radiator to prevent flow from coming into the fan from the gap between the fan shroud and the radiator. So check that. If yours has a gap there, then the fix is to loosen the shroud and put some sticky backed weatherstripping foam tape into the gap all the way around and retighten the shroudso that it compresses the foam. Now the fan has to pull all of its air through the radiator.

That worked, but wasn't perfect. The next thing Yanmar suggested was not very intuitive, but it turned out to also help fix the problem. It turns out that the screen on the front of the radiator was putting enough resistance to the air flow that even when the screen was completely clean the air was being pulled from the edge gap between the screen and the radiator. When that happened, instead of an air flow straight through the radiator, most of the air was turning and going past only the outer cooling tubes of the radiator. Those were doing their job, but the rest of the radiator tubes weren't getting much air flow. There again the fix was sticky-backed foam tape. This time the foam tape is placed to seal the edge gap between the chaff screen and the radiator. Same principle.
Here's a tech bulletin that will give the general idea:
rScotty

 

[clemsonfor]

not many (if any) radiator shops left around me. only does large trucks, or heavy equipment.
With all these new radiators now being made with mostly plastic and aluminum for vehicles, most radiator shops have gone out of business

that's why i say there a dyeing breed and if any are left. And yes most of them do equipment now a days where the radiators are hundreds of dollars and easily thousands when you get into big stuff.

 

[denchen]

This might sound crazy but......you could try adding a stronger portion of antifreeze to the radiator solution. It is a fact that glycol, used in the make up of some antifreeze, attracts heat much more than just water, but at the same time it gets rid of the heat much faster. If you look at the old spitfires and hurricanes that flew in the last world war, they were run on nearly pure `glycol` because they only had room for small radiators, and they had big engines. There is a down side. If you have a weak wall in the cooling system, the glycol will find it. And if you get shot at, there is a bigger risk of it catching fire. Also beware, if there is a fire, the flame will be almost invisible.

 

[clemsonfor]

Yes, cooling was a problem with several old YM models. It was barely adequate in spite of the pretty good hi-copper brass that they used to make the radiator Yanmar published several technical bulletins on this. There were two fixes:

One problem was that on some models the shroud around the fan was not air-tight enough against the radiator to prevent flow from coming into the fan from the gap between the fan shroud and the radiator. So check that. If yours has a gap there, then the fix is to loosen the shroud and put some sticky backed weatherstripping foam tape into the gap all the way around and retighten the shroudso that it compresses the foam. Now the fan has to pull all of its air through the radiator.

That worked, but wasn't perfect. The next thing Yanmar suggested was not very intuitive, but it turned out to also help fix the problem. It turns out that the screen on the front of the radiator was putting enough resistance to the air flow that even when the screen was completely clean the air was being pulled from the edge gap between the screen and the radiator. When that happened, instead of an air flow straight through the radiator, most of the air was turning and going past only the outer cooling tubes of the radiator. Those were doing their job, but the rest of the radiator tubes weren't getting much air flow. There again the fix was sticky-backed foam tape. This time the foam tape is placed to seal the edge gap between the chaff screen and the radiator. Same principle.
Here's a tech bulletin that will give the general idea:
rScotty

i wonder if this was more model or engine specific? There are so many of us. I live in SC and routinely will bush hog on very hot summer days, easily 95F+ for hours and , knock on wood, have never had a problem other than when i first got my tractor and did not clean the fluff, seeds and grass and such from the screen often enough.

 

[kenmac]

There are several products on the market that aids in cooling. You might want to try one of these products.
I use to use water wetter in my race car. Now days,I'm sure there are others on the market.

My yanmar only runs hot when the radiator grass seed build up..

My kubota also gets hot when grass seeds get in the radiator.
I have to stop several times and wash out the radiator on the kubota

 

[rScotty]

i wonder if this was more model or engine specific? There are so many of us. I live in SC and routinely will bush hog on very hot summer days, easily 95F+ for hours and , knock on wood, have never had a problem other than when i first got my tractor and did not clean the fluff, seeds and grass and such from the screen often enough.

Going back through the Yanmar tech bulletins, it's easy to see that the overheating problem was specific to several models made by Yanmar during that era. No doubt it is going to depend a lot on the particular tractor & how it is used & all the rest of the radiator cooling system.

For instance on thermosiphon cooling systems (no water pump) used in early Yanmars, the amount of ethylene glycol that is to be mixed with water is limited ot 40 or 50%. That's because glycol has a lower heat transfer coefficient than water. So even though glycol has a higher heat capacity it still doesn't work for cooling as well as water because of the transfer coefficient. Once all the arm waving and calculations are done, the result is that a higher percentage of water makes for cooler running. However... the difference in cooling that you lose with 50% glycol instead of pure water is only about 5%. For a tractor working hard, that comes out to about 10 degrees F.

I'm an old-fashioned guy, and I'd have to say that anyone who designs a working diesel engine with a cooling system that works so poorly that a 5% difference in cooling makes a difference....well, that person needs to go back to engineering school and re-take the required course in thermodynamics.
There are plenty of thermosiphon cooling systems that work just fine. Including some other brands of tractors. None that I know of are as finicky as Yanmar's system.
I like Yanmars, but that doesn't stop me from seeing their flaws.

Hey! Is anyone else here old enough to remember when it was common practice to put specially cut pieces of cardboard in front of the radiator of both cars and tractors in order to get them to run at proper heat in the winter?
rScotty

 

[CalG]

If I may inquire.

What is the "correct" engine coolant temperature, and how has that been determined? From My understanding, Engines work best at "higher" temperatures, and pressurized radiator caps and high boiling point coolant mixes were developed to meet this requirement.

The "green bar" on the temperature gauge is a farce unless calibrated against a known good reference, such as boiling pure water. or according to the coolant, anti freeze mix guidelines.

Feeling good about coolant temperatures below the boiling point of pure water is foolish. Cooler is NOT better.
Find out the facts! Report back.

Blown head gaskets are an entirely different issue!