Questiontruck is overheating. have changed thermostat,backflushed,new 50/50 fluid,no oil in water,no water in oil, new thermostat,water level stays good,radiator cap appears good, water pump no leaking-assume it's ok, hoses appear ok but top hose gets very hard to squeeze when I tried to test if therm is opening, fan clutch "appears" to be ok, when truck gets hot it starts using alot of gas, haven't replaced the water temp sensor, temperature will stay at acceptable range if I turn heater on full blast and don't go above approx. 60mph.
AnswerYou have a coolant circulation problem and I have a feeling it's the radiator that is the cause of it, it may be clogged partially, I recommend that you remove it and have a radiator shop open it and clean the core if possible, if not it may have to be replaced. If the radiator is ok replace the water pump.
