90 Ford f150 5.0 engine gets hot?

The radiator is full, the water pump is working and circulating, the belt is good and fan is working, I get hot air when heater is turn on, I do have the thermostat out of it because it was sticking a while back. So I'm stumped on this one. Anyone have any suggestion what I'm over looking

My 2004 Ford F150 was running fine on good Friday, and the next day Saturday evening my motor was tapping?

My 2004 Ford F150 was running fine on last Friday, and Saturday evening my lifters was making an loud nocking sound, I took it to an mechanic and he told me its my lifters, or the cam phases, It seems impossible for that to happen in one day. I have 148,000 mile on the vehicle. Like I said it was running fine on good Friday. My mechanic suggest that I don't fix it and buy an new motor. Can anyone help me on the situation