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656 diesel overheating


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Have you used a radar temperature sensor gun to verify the temperature gauge is correct? Or how do you know it's definitely overheating? 

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How clean is the hydraulic oil cooler? Could be restriction on the air flow if those fins are slightly blocked? Also if it's running really lean fuel wise it makes more heat

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Have you checked for combustion leakage into cooling system.  Would have been best if done while thermostat was out for better test.  But, loosen belt to water pump so pump cannot turn and have coolant well over the core in radiator.  Best if filled right to top of neck.  Start cool engine and watch coolant level.  It should not move or bubble .  Best to rev the engine up and down because that puts a lot more pressure in the cylinders . Test has to be short like less than a minute or normal warming of engine will raise coolant level.  

Those head gaskets are bad for leaking into coolant.  You could test each cylinder individually by pressurizing through glow plug hole but that is a lot more work but a better test. 

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Pete23 is probably on the right track

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42 minutes ago, bitty said:

Pete23 is probably on the right track

went thru 3 h/gs in our 282 Ds and sent them on down the road and got different tractors/engines - got frustrated with them 

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I F----d up one time and put in a thermostat upside down.... As in the bulb part was away from the hot side of the coolant flow and would not open when it should. Spent a lot of time and money to figure out my own mistake..

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What about the condition of the belt and water pump pulley? Some of these can get pretty smooth and slip enough to not spin at a good speed. Does this happen when working the tractor or just putting around the yard?  Did you accidentally leave a rag or plastic plug in the coolant hoses? Are they collapsing or squishing down? How about your radiator cap? Is it holding pressure and not leaking? If put some pressure on it and the radiator using a tester and see if you have any leaks or blockage. Oil cooler would be a fluid fluid type exchanger on the side of the block, so I would think that's not your culprit. Fan blades look good and hold their shape? I used to have a 79 Ford that would over heat when I turned the lights on. Single belt run it all, so the extra drag on the belt caused it to slip on my harmonic balancer pulley. It was well glazed over and the belt was old and wouldn't hold tension. I replaced them both and it quit overheating.

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8 hours ago, pete23 said:

Have you checked for combustion leakage into cooling system.  Would have been best if done while thermostat was out for better test.  But, loosen belt to water pump so pump cannot turn and have coolant well over the core in radiator.  Best if filled right to top of neck.  Start cool engine and watch coolant level.  It should not move or bubble .  Best to rev the engine up and down because that puts a lot more pressure in the cylinders . Test has to be short like less than a minute or normal warming of engine will raise coolant level.  

Those head gaskets are bad for leaking into coolant.  You could test each cylinder individually by pressurizing through glow plug hole but that is a lot more work but a better test. 

Pete, would that cause his gauge to show hot? I'm asking not questioning. I've got a 656 that I've asked about before that likes to spew over from time to time but never overheat. Knowing the animal I did your test minus unhooking the pump. It didnt occur to me to do that and I like it. I think I'll redo my test like that. 

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26 minutes ago, Missouri Mule said:

Pete, would that cause his gauge to show hot? I'm asking not questioning. I've got a 656 that I've asked about before that likes to spew over from time to time but never overheat. Knowing the animal I did your test minus unhooking the pump. It didnt occur to me to do that and I like it. I think I'll redo my test like that. 

If you have a combustion leak into cooling system , it gets hot and depending on how large the leak as to how fast it will get hot.  Testing with water pump turning is not a good test .  Also, this test is just a simple quick test and if you see no real sign of combustion leakage, then you start looking at other problems. 

Spewing over usually but not always accompanies heating and I have always said that cooling systems are one of the hardest problems to find a solution to.  IH had a lot of problems with the 66    series spewing over, usually when throttling down after working hard. They changed the baffle in the radiator to overcome that problem.  In the meantime with original radiators, we put on expansion tanks mounted on the pre cleaner baffle that is in front of the radiator.

One other thing.  The original radiator cap on 06 series tractors on up was changed to a NON spring loaded atmospheric valve. Most caps after a few years let that valve (the little disc in center of cap) dangle so low that it never moves up to shut off and allow pressure to build in cooling system.  That alone can cause spewing on occasion.  I replaced a lot of caps with the spring loaded valve because we want that cooling system to operate under pressure .

I also went with a 7 psi which I feel is plenty as we never want those engines to run 220 degrees so you don't need 10 psi cap.  The reason IH changed to non spring loaded atmospheric valve was people were noticing those long rather soft top  radiator hoses would get sucked together when engine cooled off.  Didn't hurt a thing as it was the top hose and just popped right back out when running but didn't look right.  

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Joe, my experience with a JD 466 combine engine several years ago drove me nuts. Somewhere in the middle of our six week harvest time the water pump seal let go. I replaced it with a rebuilt pump from the dealer and by mid morning day one it was showing temp. Shut down and it was spewing out the overflow tube. Next I replaced the main hose and thermostat thinking the hose had collapsed, stat for good measure. Fired up, same deal...what the ****? Pulled pump off, clamped pulley flange in vice and poked at the impeller with a hammer and punch. Impeller loose on shaft! Next rebuilt good to go. If you get that deep into it would recommend looking at that impeller. 

 

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