M operating temp

JASFarms

New User
Ive got a 1941 M that idled, I thought, too warm. Itll run just to the right side of center on an IH coolant temp gauge. I checked the belt tension, and replaced the thermostat and radiator cap. I also drained and replaced the coolant. Nothing helped it.

So I took the IH gauge off and replaced it with a generic numerical gauge and it is telling me that it idles around 195 and runs just under 190 at fast idle. Should I be concerned? I assume the radiator would be the next step. Have it boiled/rodded out or replace it or do nothing? I need the old girl to auger 15,000 bushels of corn this fall and then its back to hibernation. Thanks.
 
Drain the cooling system and fill it with white vinegar and run it till good and warm. Let cool then if you can rig up a way to back flush it by way of the block drain. I have an Oliver 77 that would over heat and after I did that it has not overheated again
 
I agree with old on that one, i did that with my 806's runs
cool now! And it wont hurt anything as far as hose's or O rings!
 
I wouldn't call that overheating. Although I have never had an M, I've had lots of experience with H's. With a thermostat in, that would be its normal operating temperature. Now if it gets much hotter under load, you may have a problem. Those engines were designed to operate at a temperature that hovered around where water boils because that's where they are most efficient. Old "thermal-syphon" radiator systems didn't have heat gauges because IH design people didn't want you to know how hot those engines were running.
 
That seems real hot for that style if it has bypass hole like an H.

I keep meaning to make a bypass block plate for mine, maybe a solidworks and CNC winter project coming.
 
The way things go now days NEVER assume it is what it should be since many parts are made in the land of almost right plus many people selling parts should not be doing that job due to not knowing a machine
 
Yep under load it would heat, so hes got calcium build up, i put in a restrictor plate in my M to slow down the bypass, it's my loader tractor, it wouldn't come off cold most short trips, but with the restrictor plate get up to the green now putzing around the yard,in the summer,and had it in last winter too,just right! That was Jim N. suggestion and worked great!
 
That would be about normal with 180-190 thermostat and block plate, not at all normal without block plate irregardless of thermostat temperature. The bypass lets so much water flow the thermostat only works under load.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top