Newly Rebuilt Tractor Overheating

[dirtdonkey]

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.

 

[winston1]

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.

 

[90cummins]

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

 

[Barry 1]

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.

 

[284 International]

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.

 

[California]

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.

 

[284 International]

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.

 

[Car Doc]

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.

 

[kenmac]

Can't remember exactly ,but don't the light come on around 225-230 deg ??

 

[clemsonfor]

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.

 

[dirtdonkey]

Thanks for everyone's comments. There is no thermostat in my motor and the elbow is part of the head so there is no where to mount one, that I can see. The radiator and cap were brand new, when I rebuilt the motor and only have 3 hours running time on them. I flushed both the block and head when they were apart and didn't notice any restriction in flow running water through them. My first thought was the head gasket so I took the head back off. Cleaned everything and then checked to make sure the block was flat to match the head, which I had planed when it was redone with 2 new valves in the #1 cylinder. I matched every water jacket hole to the gasket to make sure nothing was blocked. I have no water in oil and there are no bubbles when the motor is running and if I'm only using the tractor lightly then it doesn't overheat. It only occurs when I'm running hard pulling motor up hill and running 80-100% throttle. When I back off throttle and run easy it stops overheating.I called Hoye, where I bought my parts, and they suggested the mechanical temperature gauge I bought could be wrong. I bought the following Kintrex IRT0421 Non-Contact Infrared Thermometer with Laser Targeting and checked it when I received and it appears to be working correctly when I measured it against things I knew the temp of. When I ran the tractor the other night I filled the radiator to full and emptied the overflow tank completely. Started overflowing the overflow tank about 1/2 hour into the mowing job. You also notice the bubbles in the tank when it gets this hot. I was thinking of adding an additional shim to my injector pump to ****** the timing and see if that helps but wanted to try everything else first before I resorted to that. The tractor starts and runs great, minus the temp problem. I've replaced the radiator cap with 2 others last being 15PSI but no luck.

 

[winston1]

Doesn't seem to be any doubt for some reason it is boiling with hard work. What doesn't make sense to me is the temperature readings you are getting. I have an el cheapo Harbor Freight non contact thermometer and my 2002d runs hotter than your readings and doesn't boil over. I'm thinking the hottest area of the cooling system should be right at the neck where the top radiator hose leave the water pump area. What do you read there when the boil starts?

 

[careyo63]

Try a local big chain auto-parts they may rent or even borrow one of these. Another method is using a home made tester since it seems to be only doing it under a working load. Your need one like the Radiator cap but with a Gauge. Your know whats happening when it occurs. Lack of water? Pressured up? Lack of or restricted flow of Air? Could be a Cracked Block, Head etc. Your be able to watch how fast it looses pressure. Have I done this before?
Make an Auto Radiator Pressure Tester

 

[Car Doc]

Its obviously got a water pump what condition was the impeller in or did you even have it apart? Its sounding more and more like a circulation problem either there is no/low water flow out of the water pump or a restriction. How about the hoses coming out of the block/water pump any chance you mis routed the lower ones? On mine the front hose of the 2 coming out of the water pump goes to the lower radiator and the rear hose out of the wp goes back to the block.

You mentioned going all the way up to a 15#... well a water pump is centrifugal and will make that much and more pressure with no problems if the return is restricted. It will pump coolant out because it has no where to go if there is some restriction the rad cap is the easiest path just food for thought.

\\just for conversation but This is just an example of things that can happen-we put a cam in a chevy pickup a long time ago and my helper was the one that put the radiator in. Well he forgot or didn't see it to pull the cap plug out of the lower pipe on the radiator when he installed the radiator. It would idle fine and stayed at a somewhat normal temp but as soon as we take off down the driveway it would creep up to hot pretty quick.

I also noticed that with the radiator cap off revving the engine coolant would overflow the top of the radiator and when looking back that was a dead giveaway of the underlying problem.

After work while I was the only one there I started dissecting the truck. Well I noticed when I took the lower hose off coolant only came out from the block side BINGO found it. That's one another was a chevy van that had no impeller at all completely rusted off. The customers complaint was no heat it never ran hot just no heat above 10 mph at a stop it had a little. That one took me awhile to figure out. My point is dont overlook things you believe must be ok check everything. :thumbsup: good luck

 

[clemsonfor]

I had an older mercedees 300D in college. I was 5 minutes from my uncles house one night and all of a sudden a horrible screech and then nothing and all the lights for things like batteries came on and my alt gage pegged on the low side. Well i knew something had locked up what the screech was and then burned the belt off. Engine was still going fine so i kept going hoping that the belt to the waterpump was still fine, well no dice, it started creeping up instantly and i just kept going till right before it got to hot and pulled over. Was in the middle of the country and walked about 1/4 mile to a hill top to get a broken cell call out to my unlce to bring a chain to pull me to his house. Next day i started to pull it apart in the yard at that point it was obvious the problem was the WP it had seized up and thats what started it. So i pull it off, and what comes out behind it, but a mercedees bolt that looked like a WP bolt, but also fan bolts and many other bolts that size on the car. Where the heck did that come from? Was is dropped in the radiator and made it to the pump? or did it come out of the block on an engine redo (not as likely). But once i found that it was fine, the impeller was chewwed up from where it had not worked in just the right place to jamb the impeller, so i replaced it.

sorry off track but just another story that will make you scratch your head.

 

[SailorBob]

I rebuilt my YM1700 a few years ago. I retourqed the head bolts after about 10 hours. 300+ hours later all is well. I would try that before panicking.

 

[Car Doc]

Yeah I agree re-torquing is probably a good idea it sure wont hurt anything and a re-check of valve lash since he is in there.

edit: I am almost certain its going to be a circulation problem either a bad new radiator or defective water pump, could even be a passage blocked by something foreign maybe a gasket is wrong even. There is still a fair chance its just a temp sensor problem. my .002

 

[dirtdonkey]

When I rebuilt the motor I installed a new water pump. I started today, with no radiator cap on and there is definite flow across the top of the radiator. I mowed for about 1/2 hour and it overflowed into my overflow tank, which I had started with empty. After 3/4 hour the overflow tank was overflowing. The temp gauge never got above 190? I'm going to take all hoses off the motor and check to see if anything is wrong with them in any way. I spoke with Matt at Hoye and everyone tells me he has a lot of experience with Yanmar rebuilds and would probably be the best person to speak with about my problem. I went over everything I'd done and the temps I'm seeing on the metal parts and he says it doesn't make sense. The temps I'm getting should not be making anything overflow, like I'm experiencing. I guess this coming weekend I'll retighten the heads to make sure and then take off the hoses and flush the block to see if anything comes out when I flush from the Neck coming out the head back through the block. Then I'll flush the new radiator to see if anything appears blocked. I'm really at my wits end. The motor is performing perfectly. Starts with first bump. Oil is perfectly clean with no spec of water in it. If it wasn't for the overheating I would have a perfect scenario of a rebuilt motor. I'm sure we'll get to the bottom of this but it is frustrating getting there.

 

[284 International]

With the information you gave, my bet would still be on a blocked radiator, in some way or another. I think you should take the radiator out and stick a hose down the fill neck and turn the water on full blast. The radiator should easily flow all the water from a large diameter hose, without bubbling back out the fill neck. If it checks out, then you have a cracked sleeve, head, or a head gasket issue (Whether improperly installed, blown, etc.)

The 1/2 hour of operation before it bubbles over to me strongly implies that the engine isn't being sufficiently cooled. I think if the head gasket were bad it would bubble instantly, or, at the least, a few minutes after startup, once all the engine parts were at operating temperature.

Have you cleaned the radiator screen of chaff, and made sure there is nothing blocking air flow through the radiator? Is the fan in good shape, spinning properly, etc? Does it still have the fan shroud?

I also think you should get some water boiling and verify your IR thermometer is functioning properly, too.

Keep your chin up! You'll get it figured out!

 

[kenmac]

Hang in there man. You,ve come too far for something like this to happen. You'll find it.You may have already checked this ,but is Radiator hose collasping when hot ??