I have a 2000 ram 1500 with a V-6. What temperature should I be running with AC on and a 90 degree F day. My temperature gauge appears to read warm, I would guess reads 240 degrees F. New thermostat is 2 years old. New water pump is 3 years old. Late last summer the radiator started leaking so I put in some stopleak. Is the radiator causing my overheating problem? I want to replace my radiator but I want to make sure my problem is fixed.