Mahindra Temp guage

[dnetherland]

I have 1999 Mahindra 4005 tractor. The temperature gauge will show 225F (halfway into red) degrees after running about an hour. I have changed the thermostat, coolant, cleaned the radiator and air filter. I have also used a laser temp sensor which shows the radiator to be 200F or less (green) and there is about a 10-15 degree drop in temp from left to right on the radiator. Temperature on the block also appears to be 200-205F. Area immediately adjacent to the temp sensor also shows 200F or less when the gauge shows 225F. I have changed the temp sensor and gauge as well as the wire from the temp sensor to the connection for the wiring harness just forward of the firewall. I also changed all the fuses in case a drop in voltage to the gauge was causing a faulty indication. I have taken the tractor to a dealer twice now and they have not been able to confirm the problem (probably because the tractor has to be under load for an hour or so before it shows hot) nor have they fixed the problem. I am a weekend farmer and need to run for 10-12 hours at a time so an accurate temp gauge is extremely important to me. Do you have any suggestions?

Don Netherland
e-mail n95sl@earthlink.net

 

[Fredex]

Have you considered the possibility that the radiator core tubes might be partially plugged? Or maybe the water pump?
I think the best way to measure the temperature gradient across the radiator would be to compare the temperature at the top location where the hose from the engine enters to the temp at the bottom where the hose feeds cooled coolant back to the engine.

 

[Down Under]

Hi There Mate,
Have you tested your temp sensor outside of the block. Put it conected in a pot of boiling water to test its acuracy and then if its telling you the truth you can move on to the cause.

Regards Alex.