well i have tried 4 different caps and none solved the problem.the one i have now is from the crysler dealer and was ordered by the vin number, so it should be correct.as for cracks i cant see any and i had it pressure tested and it didnt show any leaks anywhere.that makes me think something is clogged up or something.there seems to be some noise coming from the water pump and i have heard that the blades in it can get worn out causing it to slow down or stop.that makes it build up pressure, but is letting enough through that it doesnt overheat.
also, i have seen on some other forums(through web surfing) that people that have had this problem fixed the water pump and thermostat and their problem was solved.
i get what your saying, and yeah it confuses me too, but id rather get the water pump than just go buy a radiator somewhere.that can get expensive.
on the other hand me and the place i got the truck from have been having some issues just because they sold me a truck that seems to never have been taken care of...i was able to get enough money out of them to get the stuff to change my ball joints and a water pump(in other words its not my money haha) so since i have it im gonna try it.im not losing any money on the deal so i might as well try it.
any other suggestions on what it might be though?im lost.