Anti freeze I put in said to use a 75/25 mix
This has got to be your problem.
Check the container. If it says 100% glycol, you need a 50/50 mix. I don't care what the container says about mix ratio. If you put a 75/25 ratio in, you're definately going to be running on the upper range of operating temp. I'm willing to bet, if you put a 50/50 mix in, this will correct your problem. You could just drain out a gallon, and, add a gallon of water.
See if it works.
JS
