The past two times I have pulled the car out of the garage in the past month the upper rad hose has been hard as a rock cold and I had a small leak of coolant from the hose @ the radiator. Usually the hose remains somewhat flexible cold and hot and the car runs great. I replaced the hoses, thermostat, water pump and rad cap last summer when we go her and have never had an issue before.

Last week I took off the rad cap, and ran the car to see if there was some air in the system possibly. Used the car later that day and following day and no issue with the upper hose being so firm.

Could this all be due to a lousy cap? Or am I in the midst of a potential head gasket problem? The coolant is green and the oil is clean as well. No smell of coolant in the exhaust either.

I do have a small intake manifold leak that I need to address, would that cause this?

Thanks
Ed