Just bought an '04 with over 200,000 miles. I am having to add about 1/2 gal. of coolant a week. I can see steam coming out of a rubber hose underneath truck. Cant tell where the hose is coming from but it sticks out in the front of the engine. The radiator hose doesn't seem to hard. It just had the injectors replaced, not sure about the cups. Any ideas? Thanks for any help.