Harrygoodwrench
Gold Member
Just my opine but the way you just described it sounds like the thermostat is opening late and is defective. Thermostats can fail in so many ways as described above. I'll bet I've replaced hundreds of thermostats in my mechanical career. It is really amazing how a thermostat works.
For those that want to/or care to know how the thermostat works here it is. The thermostat is a thermal bulb with a blend of about 27 paraffin waxes that expand at different rates. It is the mixture of the blend that determines the opening rate of the thermostat. A properly operating thermostat will just begin to open at its designed setting and gradually open to full open at approximately 10 degrees of its beginning setting. Same when cooling down. Generally in an automotive application(which a tractor is) it is always somewhat modulating to the opening. Unless, you are operating under full load or extreme temps then it would always be open, or closed, in severe cold temps and thats why the bypass system is there so coolant can flow when the thermostat is closed. The main reason for the thermostst is to get the engine to "designed" operating temp and help keep it there. That is does pretty well.
Replace the stat and give us the results. /forums/images/graemlins/smile.gif
For those that want to/or care to know how the thermostat works here it is. The thermostat is a thermal bulb with a blend of about 27 paraffin waxes that expand at different rates. It is the mixture of the blend that determines the opening rate of the thermostat. A properly operating thermostat will just begin to open at its designed setting and gradually open to full open at approximately 10 degrees of its beginning setting. Same when cooling down. Generally in an automotive application(which a tractor is) it is always somewhat modulating to the opening. Unless, you are operating under full load or extreme temps then it would always be open, or closed, in severe cold temps and thats why the bypass system is there so coolant can flow when the thermostat is closed. The main reason for the thermostst is to get the engine to "designed" operating temp and help keep it there. That is does pretty well.
Replace the stat and give us the results. /forums/images/graemlins/smile.gif