Ok, we have a John Deere 1040 tractor here (2.9l 3 cly diesel I think) and I'm a bit worried about the coolant temps.
The tractor has a murphy switch on it so if the oil pressure drops or the coolant temps get too high it kills the motor. What I am worried about is the sensor for the coolant is on the return side of the rad. It is set at 220F. We were running it stationary at full throttle for a few hours and I noticed that the murphy switch was reading 210 but the coolant coming out of the head was 230.
Is this too hot?
The day before it was 250 out of the head and 230 at the murphy switch (someone has bypassed it
)so I took the load off and let her cool down at idle. She seems to be doing ok. I changed the thermostat, topped up the coolant and washed the rad out and it seems to be running cooler now. (still 210/230)
Also what is strange is when it's that hot, I can put my hand on the front of the rad and hold it there for 5 seconds before it gets uncomfortable. I measured it around 145-160. The back of the rad is 205ish. Is that normal?
All temp readings are with my infrared thermometer except for the murphy switch readings, they are an electronic reading.
Is the coolant significantly less hot on the OUT of the rad as it is opposed to the IN of the rad?
Maybe the radiator is not doing to well at cooling, is there a shroud around the fan?
Usually isn't it at 240f that is the top temp for Nascar to make power and they start to say the blocks can deform around 260f? They have race stuff but run the races anywhere between 220-240f but 250f is hot for one to run at non race.
Is the rad a double row and hooked up so the front is cooler than the back?
My favorite snake oil that works is Water Wetter, from Redline. It will cool it down, but enough for your liking I don't know.
The coolant is 20-30 degrees cooler coming out of the rad. It could be a double row rad, I'm not sure.
There is a shroud.
I was thinking 220 was the top of safe, but if I'm good up to 240 then I guess I'm doing ok.
That is from what I have heard, but they are full race and set up for it. I get nervous there, but I have seen where a gas engines valve cover was cherry red the engine was so hot, wouldn't shut off with a key and it was fine afterward somehow. Your tractor seems a bit hot and need of close watch, but I don't think it is going to die from those temps. Jeep xj with a 4.0 always ran at 215f *with a/c I saw it as high as 230f*, chevy 2500 runs around 210f, and most all my other stuff runs under 190f.
I just checked the max temps for my truck (F250, 6.9l) and they say 240 is the max. I figure my truck engine is built similarly to the tractor engine so it's probably ok. Scary but ok. As long as that murphy switch does it's job everything should be fine...