Why does your jeep overheat only when towing your boat?

It requires more power on the part of your engine to pull a heavier load. When you are pulling a heavier load, your engine uses more gasoline and produces more heat. At that point it produces more heat than your radiator can get rid of. If you tow your boat a lot and will continue to do so, you may need to get a larger radiator. That way you can get rid of the excess heat. Also you can turn off your AC and open your Windows when pulling your boat. That will also help. Make sure you are running 100% coolant and no water. Check your hoses. Sometimes a hose will close just a little bit. That will cause a mess.