Newly Rebuilt Tractor Overheating

   / Newly Rebuilt Tractor Overheating #1  

dirtdonkey

Member
Joined
Sep 22, 2012
Messages
35
Location
Dade City, FL
Tractor
2012 Mahindra 4530
I recently rebuilt my Yanmar 3110D. The tractor runs great after the rebuild. I installed a new piston in number one cylinder. New rings in the remaining 2 cylinders. Head was redone with new valves in Cylinder 1. Head was planed so it is flat. The block was checked and it is flat also. I was mowing today, 6' Rhino mower, and motor was running 2000 to 2400 RPM most of the time. Temperature guage reads 190 degrees at its hottest. Overflow tank was empty when I started mowing and continued to get fluid from radiator coming in to it and was bubbling in the overflow tube. I have a remote sensor temp guage and checked everything when I noticed the overheat. Radiator showed 140, water pump area showed 180, head showed 190, exhaust area of head was highest and at one point right at exhaust area of #3 temp was 240. Hard to tell weather the fluid side is that hot or not and temp would vary depending upon where you got the reading. That is the only area I could find that was over 210 anywhere. This was after running for over an hour mowing grass. I'm wondering if I don't have a bad radiator and cap fit, even though I just installed them new, when I rebuilt the motor? Really can't figure out why its overheating. Was thinking about adding another shim to the injector pump to ****** the timing but timing appeared correct when I did the reubild and checked it. Any suggestions greatly appreciated.
 
   / Newly Rebuilt Tractor Overheating #2  
The temperatures you are reading do not indicate your tractor is overheating. If you have continuing bubbles it is more an indication of a blown head gasket. This assuming your new cap is holding properly.
 
   / Newly Rebuilt Tractor Overheating #3  
90cummins
If the head & block checked out OK and it is not losing coolant into the exhaust or oil then it’s possible that the head gasket is defective, or it may be missing a coolant passage that the original gasket had.
Did you try re-torqueing the head bolts?
Is it possible to install the head gasket upside down?
Is coolant or air flow thru the radiator restricted?
Another possibility may be the water pump is not circulating the coolant properly; a coolant hose may be internally restricted, collapsing or improperly routed??
90cummins
 
   / Newly Rebuilt Tractor Overheating #4  
Sounds normal to me ,unless the bottle is overflowing? You have to keep antifreeze in the bottle.It takes several cycles of heating and cooling to work all the air out of your motor.
 
   / Newly Rebuilt Tractor Overheating #5  
The radiator reading of only 140 degrees seems low to me. I bet your radiator has some blocked coolant passages. The fact that the coolant is bubbling seems to be a key. The choices are that either compression from the cylinder(s) is leaking into the coolant passages, or the coolant is reaching its boiling point.

Since your reading from the radiator is only 140 degrees, I'm strongly leaning toward that part of the radiator simply not seeing much, if any, coolant flow. 140 degrees certainly is nowhere near boiling, but if compression were leaking into the coolant, you would boil over all the time. I think you have an obstructed cooling system, and that pulling the radiator and having it properly rodded out and cleaned at a shop will prepare your machine for another 30 years of service.
 
   / Newly Rebuilt Tractor Overheating #6  
I'm wondering if I don't have a bad radiator and cap fit, even though I just installed them new, when I rebuilt the motor?...
Any suggestions greatly appreciated.
New radiator, or just the cap? Actually, that the cap won't hold pressure is irrelevant if the temperature never reaches boiling. The only reason for a pressure system is to allow a higher boiling temperature.

I agree with the theory of restricted coolant circulation, if the radiator core shows only 140 degrees after running it hard. Take off the radiator cap before the engine is hot and verify that you see water entering from the top hose. Also look for bubbles which would be exhaust in the water.
 
   / Newly Rebuilt Tractor Overheating #7  
On further contemplation, it is also possible that your temperature reading device isn't reading properly, and that the coolant in the radiator really is over boiling. A good way to test it may be to put a glass into the microwave and heat it until the water is boiling, then see what the gauge measures with a known reference point.
 
   / Newly Rebuilt Tractor Overheating #8  
The cap being bad is the first thing comes to mind with the fluid moving maybe excessively. The air in the block will bubble out thru the overflow bottle that's normal on any closed cooling system as it heats up and expands and it should pull some back if its got the right cap these need a 13# least mine does, and 190 is not overheated at all.

I can tell you that w/o question these are hard to get all the air out and keep a consistent level in the bottle between hot and cold. I have even vacuum filled mine and know exactly what the level in mine actually is supposed to be and it varies from the low mark to high mark where it is from time to time.

This is another thought- I have a thermostat on mine I am not sure on a 3110 altho its the same basic engine as me so if it has one that is another good possibility its bad being 30 years old. (Mine was sortof overhauled before me and it had a junk OE one still in it for what they cost it isn't a good idea to trust them.) I put a 1 1/4" 180 degree from Oreillys its very very close to OE specs being SAE vs Metric fyi.

Where did you tap into it for the temp sensor? Is it mechanical or electric? I agree with the it may be reading wrong or a circulation problem (thermostat/radiator) crowd.

I watch mine close and unless I get it good and warmed up it will not pull coolant back in the same amount that it pushed into the bottle so what I am saying is the level may varie and still be ok. You might put some Wixcool in it also since its got wet sleeves its not causing any trouble now just a preventative measure since you probably put new coolant in now is the time.
 
   / Newly Rebuilt Tractor Overheating #9  
Can't remember exactly ,but don't the light come on around 225-230 deg ??
 
   / Newly Rebuilt Tractor Overheating #10  
Yea, Kenmac, i think your right i dont remeber what the guys say but 212F is normal boiling (i know you know that) in an open system NOT under pressure. I think the 13PSI or whatever cap would easily raise the boiling point to 220F ish? So to me that Number makes sense.
 
 
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