# mitsu 2350 overheating problems



## rj'sbarn (Jul 30, 2008)

Hello all. I have areconditioned mitsubishi 2350fd that has had a laundry list of mechanical problems. My latest conundrum, and the one I need help figuring out, is why my stuff keeps overheating. 230 degrees after 10 minutes of operation is the norm when brush hogging and 30 minutes to reach 230 when finish mowing. I am thinking about checking the coolant for combustion gasses or looking for a non-obstructing upper hose thermostat adapter. Other than that I am clueless. Any help anyone can pass my way would be much appreciated.


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## Live Oak (Dec 22, 2003)

I would start at the beginning and verify the basics. Is the radiator fins and pipets clean. A good pressure washing should accomplish this. Has the engine cooling system had a good flush and cleaning? Get the garden hose out, open up the drain fittings (does the coolant draining out look clean and green?) ie: any oil or other crud. Flush out the cooling system. Refill with water for now. 

Fire up the tractor and go to work. Does it still over heat? If no, drain the water and refill with proper mix of antifreeze. If it does over heat. Check the radiator with a pressure tester. Does the radiator hold pressure? If not find the leak (if not able to find suspect head gasket) With pressure tester still installed on radiator, fire up the engine and get the temp up. Does the pressure build beyond a reasonable amount (5-7 lbs.)? Does the pressure gauge spike and pulsate? If yes, very likely a head gasket.

If my memory serves me correctly (and it rarely does  ) These engines can accumulate crud in the cooling system over time from failure to change the coolant and flush periodically. 

Hopefully Mark777 will see this post and jump in here and straighten us all out. Mark is a wealth of information on these machines. 

Where ya at Mark! :captain: Which reminds me that I haven't seen him post much lately.


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## rj'sbarn (Jul 30, 2008)

*overheating*

thanks for the rapid reply, admin! I have had the radiator out and cleaned the fins with water and pressurized air on several occassions, flushed the system with clean water a number of times and had my radiator vatted and cored. I have had the cap off and verified adequate coolant flow through the top hose.When it gets hot (around 210), of course the coolant will begin to burp past the radiator cap but it takes about 5 minutes of brush hogging to get there. So I wouldnt think it was being pressurized by combustion gas. I dont know.


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## mongoose_1 (Apr 1, 2006)

When it gets hot, check to be sure you do not have a hose collapsing!


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## rj'sbarn (Jul 30, 2008)

*overheating*

Good call mongoose. I'll give that a check. Gracias!


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## Live Oak (Dec 22, 2003)

*Re: overheating*



> _Originally posted by rj'sbarn _
> *thanks for the rapid reply, admin! I have had the radiator out and cleaned the fins with water and pressurized air on several occassions, flushed the system with clean water a number of times and had my radiator vatted and cored. I have had the cap off and verified adequate coolant flow through the top hose.When it gets hot (around 210), of course the coolant will begin to burp past the radiator cap but it takes about 5 minutes of brush hogging to get there. So I wouldnt think it was being pressurized by combustion gas. I dont know. *


I take that to mean you had a new core installed? If not was the old core rodded to ensure free and open passages?


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## mark777 (Jul 23, 2004)

rj'sbarn,

I strongly suspect the radiator is clogged with silt. 

A quick pyrometer, hand help electronic thermometer will immediatly show cold and hot spots once it's up to operating temperature.

It's common practice for the Japanese rice farmer to dip into the paddy and fill a low radiator without any concern for future problems that will occur later on (and most probably due to the tax incentives to replace the tractor within a certain age).

I know your tractor will cool perfectly once you've replaced or recore'd your radiator. I know of no other solution as back flushing and washing the fins only help when the radiator utilizes all of the cooling tubes.

Typically, the radiator, fully drained, only weighs around 4 lbs. We have drained and pulled them weighing close to 20, filled with mud and sent them to the radiator shop.

Mark


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## rj'sbarn (Jul 30, 2008)

*overheating*

Mark, it boggles me that a rice farmer would dip muddy water out of a rice paddy and pour that muck into a cooling system. Seems like they would be aware of the damage that could do. what I meant by "vatted and cored" was the radiator tanks were removed, a rod was shoved through each passage and the whole radiator (without tanks) was vatted in acid for a few hours. he told me the radiator was a little silted up but it was not the source of the cooling problem.Hoses checked good to, mongoose. I bought a block test kit today based on advice from a diesel mechanic and tested for combustion gasses in the coolant. I have combustion gasses in my coolant. I am pulling my cylinder head on saturday. 
Somebody wish me luck. I think I'll need it.
"prepare for the worst while hoping for the best"


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## Live Oak (Dec 22, 2003)

Just a word on replacing the head gasket and I am sure you have probable factored this in. Have the head checked for cracks, a flat true gasket surface, and if allowable a very minor fly cut to ensure she is straight, flat, and true. Ideally it is best to have the the block mating surface checked to ensure the block deck is flat, straight, and true but this is not always practical. 

Depending upon what you find when you pull the head, you may want elect to proceed with a full rebuild. Hopefully it is just a bad head gasket.


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## rj'sbarn (Jul 30, 2008)

Yeah. Got the head off about an hour ago. Couldnt wait till saturday. It may not be a full rebuild but it will be a full teardown and inspection. I have 3 shiny valves and 3 shiny spots on pistons. That explains the top end tick. Head and gasket looked good with no obvious failures, it's gonna be magnafluxed and milled. Had a lotlotlot more soot on my combustion surfaces than should have built up in 70 hours since the rebuild overseas. Reckon this could be one of those "dupont rebuilds"? God I hope not.


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## moonbeam (May 20, 2011)

*moonbeam*

My son had a similar problem with his tractor and he purchased at a auto supply store "Liquid Ice". I believe that was the name of it and it solved the problem. Where can I get a head gasket for a 2350?


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## rj'sbarn (Jul 30, 2008)

I tried some of the surfactant additives in my coolant before I finally did a combustion gas check. Combustion gas was getting by the head gasket and super heating my coolant. I got the head gasket from Valley Power in Roanoke VA. If you are having problems with an old Mitsu, Bill or Lemuel will lead you straight.


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## joedog (Dec 4, 2012)

THere is water in my oil in my 2350. Head gasket head or cracked block. IS there a way to check


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