2001 plain jane Ranger..... 2.3 L.... new coolant reservoir..new 16 pound cap twice.....fill up to max level in reservoir and 500 miles later down to min level...Check the level always with engine cold...I'm going to rent a pressure leak detector...but the coolant is going somewhere so that is just going to state the obvious ..Pull plugs and look for a very clean one????...I see no drips no smell....No coolant in oil......Has to be going into a cyl...Will it hurt to drive it? am I facing a new head gasket?.....,Help Charlie