I have a 1997 jeep grand cherokee laredo with the 318. I bought it from a friend last year. He said it had an overheating problem. I drove it through the winter months and had no issues. Now that summer is here ive had problems with it, only when pulling hills and 4 wheeling. on flat ground no issues. My friend said he replaced the water pump, thermostat, heads, and had the dealership flush the engine block, he also replaced the radiator. I have replaced the radiator cap changed radiators again and changed fan and fan clutch. do not know what else to do, any ideas.