Welcome from Chico CA!
On everyone of my trucks I pull the radiator/intercooler out and thoroughly clean the remaining coils (A/C, misc coolers such as PS) with both air and water spray nozzle. For the actual radiator and intercooler, I lay them on saw horses and clean with the air hose, then soak them with something like Simple Green or Scrubbing Bubbles and wash with the hose nozzle. I usually see a noticable change in operating temps just by making sure all these items are as clean as can be. I just did this on my '01 Dmax this last weekend and took about 2 hrs start to finish.