One of the biggest problems with the 330 rear radiator is the location of the blow-by tube which coats the radiator with oil then it catches the dust and clogs and prevents unit from cooling. I would shck the location of the tube. Many of us have extended it past the rear cap. Then I would take a good quality flashlight and have a friend or spouse stand on the other side of the radiator while you crawl in the engine side and look through the fan blades and make sure they can see the light coming through. If not you have a potential clogged radiator problem, which if taken to a shop where they take it apart to clean can be anywhere between 350 and 1000 dollars. Also check waste gate operation off turbo and make sure it operates freely, that is a expensive item since you cant just replace the gate it is part of the turbo...dont ask how I know
but CAT covered it!