[tim]

I would start by renting a coolant system pressure tester from a parts store. Check your cap and pressurize the radiator and see if they both pass. If the cap is bad replace it, if the radiator/coolant system doesnt hold then move on to a leak down tester and keep looking.

I didnt realize people copper sprayed metal head gaskets. I thought that was only done with the stock composite one. If so I just learned something new.