My truck got overheated all of the sudden when I was in the highway. I went to the side and I checked the water and it wasnt that. Ive changed a few parts and it been over a week and it still gets heated up. What should I do?
Time to visit a mechanic. You didn't list the engine size, the symptoms that tell you it's overheating, what random parts you replaced and why, or why you're still driving it like that when continued overheating is going to do serious damage to the engine. There are dozens of things that can cause overheating. How long does this take to occur? Does it overheat at highway speeds only, city driving only, pulling a trailer, etc? How long has it been since the coolant was changed? How long has this been happening? Have you checked the radiator to see if the cooling fins are corroded and brittle or if they're filled with bugs? Has any bodywork been done recently? If so, look for missing hood seals. That will allow cooling air to bypass the radiator.
If your only clue is the temperature gauge on the dash is reading too high, you might consider having your mechanic connect a scanner to view the actual coolant temperature to see if you have a gauge problem.