I notice a faint coolant smell from the radiator (passengers side) while the engine is warm. No loss in coolant, always in the middle of the two lines on the expansion tank (when cool), never runs hot. I checked the hoses going to and from the radiator, no signs of leaking. Can the radiator have a slight crack and be leaking? I'm stumped. Any thoughts? I plan on driving a 12hour trip this summer for vacation. Any help would be greatly appreciated!