Operating without a thermostat?

   / Operating without a thermostat? #11  
Esp. if it's cold out! Your find the Heater works!! Or doesn't!!...JS.;)
 
   / Operating without a thermostat? #12  
Do you guys know what thermostat will fit to Yanmar FX24D tractor? Or where to check it?
I've unscrewed the hose where a thermostat is placed and measured the diameter (44 mm) and depth (43 mm).
But what's left to check is opening temperature the thermostat should have. Is it 71C (160F) or 84C (183F)?. Does it matter much?
Of course I was searching the net, but there's no consistent knowledge about it.
Photos
1717063867463.png
1717063906850.png
 
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   / Operating without a thermostat? #13  
I'm showing HT-9155 Thermostat F-18,195,215,255. Then FX26,22,42,195,215,255,285,305
No FX24-?
Thermostat HT-9150 F17,F,20,F22,F24.
My books parts is old. Why no FX-24 ? this is Fredricks so I'm sure they know which one or both may fit for that matter.
 
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Reactions: irq
   / Operating without a thermostat? #14  
@irq I don't think it matters much. I would try to buy the higher temperature thermostat if you use your tractor at all during the colder months.

Good luck! (And welcome to TBN!)

All the best,

Peter
 
   / Operating without a thermostat? #15  
Do you guys know what thermostat will fit to Yanmar FX24D tractor? Or where to check it?
I've unscrewed the hose where a thermostat is placed and measured the diameter (44 mm) and depth (43 mm).
But what's left to check is opening temperature the thermostat should have. Is it 71C (160F) or 84C (183F)?. Does it matter much?
Of course I was searching the net, but there's no consistent knowledge about it.
Photos
View attachment 872769 View attachment 872772
84C (183F) is correct. (y)
 
   / Operating without a thermostat? #16  
Temperature is important for little diesels. The engines don't have a lot of mass, so temperatures and therefore the internal clearances do vary a lot. You want to keep them as constant as you can.
Many Yanmars are sleeve-bore, and they all have a high flow coolant system without a special bypass path like is common on big diesels.

Switching to a guage that reads out in degrees of temperature is sure worth doing. I liked to see my engines in the 180/190 F range. But not uncommon to see it from 170 to 200 - or more - depending on the work it is doing. With a gauge in degrees you can know for sure. Some winters I do block off part of the air flow past the radiator to keep the temperature up. Motors are real individualistic that way. I suspect air flow past or around the sides of the radiator is a lot of the reason. Clean the screen often.

If a thermostat fits and has clearance enough to open it will work. You can test the thermostat using a candy thermometer in a pan of hot water on the stove. Some have a smallish bypass hole in the mountng plate.
Thermostat failures are rare, but they are not precision devices. The percent opening & flow resistance can vary over a 5 to 10 degree range on some. Let us know what you find out about yours.

Don't be afraid to massage the cooling system to make it run at a good temperature.
Use 50/50 ethylene glycol/water
Luck,
rScotty
 
   / Operating without a thermostat? #17  
In Ga. I only run 35% antifreeze be careful Walmart etc. offers it prediluted 50/50.
I can say looking into it Thermostat HT-9350 is 160Deg. Ym2002 etc. uses it.
 
   / Operating without a thermostat? #18  
In Ga. I only run 35% antifreeze be careful Walmart etc. offers it prediluted 50/50.
I can say looking into it Thermostat HT-9350 is 160Deg. Ym2002 etc. uses it.
Yes, I'm glad that works for you, but the poster (@irq) is in a rather colder location (Cracow), where 50/50 glycol water is definitely necessary, based on the winter temperatures...

All the best,

Peter
 
   / Operating without a thermostat? #19  
Thanks guys for your replies. I will consider all your advices. As of now I bought the thermostat, which fits the following Yanmar engines: 4TNE88 3TNE88 3TNE84 4TNE84 4TNA78 3TNE78 3TNE68. It opens by 82 C (180 F).
My engine number is 3TNB84-UA and I couldn't find the thermostat exactly for it (by number), so I took a chance nad choose the most similar (by look) engine 3TNE84 and bought available for it thermostat. Of course, I know that looking for a missing part based on the appearance of the engine is not necessarily a good idea, but the diameter (44mm) and opening temperature (82C) are right.
1717219627122.png

As a coolant I pour the same pink fluid I use for my cars. Here's its specs:
1717223505575.png
 
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   / Operating without a thermostat? #20  
With these older engines and the changing coolants available, I think it is hard to know what the best coolant is sometimes.

Good luck!

All the best,

Peter
 

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