yanmar 1500 getting hot

[spiter23]

I have had a Yanmar 1500 for about 8 to 10 years. Never had any problem until summer before last. The idiot (hot) light started coming on- it does not come on when I use it during the winter. I have tried running straight water in the radiator, and have also tried running a product by pro-line called "ice water" that is supposed to reduce operating temp by as much as 28 degrees. Still the light comes on after the tractor has run for about 30 minutes. Have replaced the radiator cap and overflow bottle (had a small hole in the bottle). I don't know what else to try.
Does anyone know what temp the idiot light comes on ? If I replace it with a guage, where can I get one that will be easy to install? What is the normal operating temperature for this tractor ?
When the hot light comes on, the radiator is not boiling over, so maybe the tractor is not really hot? Could the sending unit be bad? It looks as if the radiator may have a couple of small cracks on the back side of it up close to the neck, but I never see any liquid or steam coming out. Need help. Thanks

 

[Tractors4u]

What kind of condition is the inside of the radiator? Does it need cleaning?

 

[normde2001]

Change the sending unit and clean the radiator, inside and out, problem solved.

 

[spiter23]

I will check that. Seems like it was pretty rusty last time I looked at the inside. Thanks for the advice

 

[spiter23]

Thanks Norm, I'll give it a try

 

[SailorBob]

The temp sensor went bad on my 1700. It would come on after running about 10 minutes and would stay on for an hour or so after I shut down the engine. Replaced idiot light with a guage. It runs about 190 degrees under heavy workload. I also had my radiator cleaned at a radiator shop. It cost $50 but, worth the piece of mind. Don't forget to clean the screen in front of the radiator

 

[MarkStewart]

Don't forget to mix your coolant 70%water to 30%anti-freeze if you haven't already. I think that model is thermo-syphon cooling.(No water pump) It will not cool correctly if the ratio has too much anti freeze. I'm not sure where you are located, but you may need to add antifreeze for winter etc. so it don't freeze up.

 

[thingy]

Try,,,BLOWING out your raditiator,,,with air,,,use one of those long air guns,,with about a 150 lb air compressor[course120,,100 would work just as good],,blow from back,,than front,,than back,,etc,,,,,than flush drain and flush your raditiator,,and fill back up with a 50/50 mix,,Also check your fan pully belt,,,I bet if you do all that,,and light still comes on,,it is nothing to worry about,,,ALTHOUGH,,could be the thermostat,,,,,thingy

 

[mark777]

Just FYI: The viscosity of 50% anti-freeze and 50% water is not recommended for Yanmar tractors. As the previous poster suggested 70% water and 30% anti-freeze is the correct ratio.

Mark

 

[thingy]

Well,,that maybe well and good,,,,,,as long as you don't go below the freezing point for that 70-30 mix,,,after all,,thats the main reason for using anti freeze,,,is to anti freeze protect it,,,right? thingy

 

[kenmac]

yea, but you also don't won't it to run hot either. thats why you have to run correct mix.(NO WATER PUMP )

 

[mark777]

Well it's about common sence and demographics, correct? If your snow blowing in winter or brush hogging in summer the ratio is 30/70.

If your at risk for freezing (storing tractor in un- heated garage) then draining the cooling system or using block and radiator heaters is recommended. I'm sure that more anti-freeze for long periods of storage would be just fine, but for operating the tractor, with either convection or pumped circulation (thermo-siphon or water pump circulation) the above ratio is recommended.

Ultimately it's the owner-operators call.

 

[Soundguy]

</font><font color="blue" class="small">( thats the main reason for using anti freeze,,,is to anti freeze protect it,,,right? thingy )</font>

Antifreeze / anti boil....

For the most part.. 70/30 works.. some have to adjust that slightly to account for colder temps.. in general.. 50/50 is too much though..

Soundguy

 

[thingy]

Well,,maybe in fl.,,but in w.va.,,it gets cold enough to freeze about there,[where ever there is],,,but,,if a 50/50 mix overheats those yanmores,,I wouldn't use it,,would just drain out a little in fall and bring it up to a 50/50 mix untill spring,[unless it would even over heat in winter?],,than I guess in half the country,,you would have to park it,,,,don't hurt my jinma none,I got about a 60 -40 mix in it,,,with the 60% being anti freeze,,ain't over heated yet this year,[or last],, the thing

 

[Soundguy]

Thingy.. your chineese jinma has a water circulation pump... Our grey market yanmars are mostly thermosyphon..( no water pump ) that is they rely upon heating of the water to make it's own circulating current in the cooling system.. same as old JD units, and some old Allis chalmers units. In those systems, if the heat density of the water is way off.. you don't get adequate circulation.

Larger grey market units.. like the 2000, etc.. have a pump.. 1700 can be retrofit with a 2000 pump.. etc.

Soundguy

 

[thingy]

I didn't know some didn't have water pumps,,,makes sense,,thicker is harder to circulate,,I guess??,,,well,,I think about a 50 - 50 mix,,is probably good down to about 30 below o,,,,so reckon a 30 - 70 mix should be maybe 10 - 15 degress,,above 0,,it does get colder than that here,,not to often but it does,,think we had several nights about 5 degrees or so last winter,,and I remember it below 0 here in w.va. not to many winters back,,one time I was in upstate n.y. in the winter,,and it was 30 below 0,,daylight one morning...thats all I'm saying,,is in a lot of the country,,a 30 - 70 mix,,might not be good enough,,,,course,,it probably wouldn't freeze solid enough to crack anything or push a freeze plug out,,???,,it would be something I would consider if buying one,,,now that I know though,,,thingy

 

[sirgknight]

i think a distilled water solution works best compared to tap water if no water pump exists.

 

[bruce1966us]

30/70 is good to 5 below zero. i use it in everything here in TN.

 

[Soundguy]

</font><font color="blue" class="small">( makes sense,,thicker is harder to circulate,,I guess??,,, )</font>

It's not a thicker issue.. but more how water current flow happens when water is heated. That's the whole principal of thermosyphon. If you change the heat transfer property of water too much.. it doesn't t-syphon well.

Soundguy

 

[thingy]

5 below,,still wouldn't feel safe with that mixture here,,,,it has gotten colder than that in w.va.,,and not to long ago,,so that means it will again,,,,,,although,,its a rare kinda thing,,,but when it is,,,its not that rare I reckon,,,,thingy