over heating issues .

[chimp koose]

Had a problem with my 98 ranger 4l on the highway . the heater bypass valve split open and dumped my coolant at highway speed . I think i caught it pretty quick but not too sure . Replaced valve ,filled her up and went for a drive . the heat went creeping up and i got it home without overheating . The overflow tank was empty so i figured i still had a bubble . Last 2 trips across town , no heat issue and recovery tank level stays the same . So today I try to go to my daughters farm and 10 min out at hwy speed and the heat starts to climb. I turned the heater to full blast and it came down but still ran hotter than normal .There was no change in the recovery tank , the system did not seem to expel into the tank. On the way home(20 min drive ) i had the heater on full and temp stayed right where it normally does . when I refilled the rad I used old antifreeze and i wonder if i got some crap in the rad? I guess its flush , fill , and a bottle of irontite in case I got a small head gasket leak from the first overheat. Opinions ? :oops:

[Crosley.In.AZ]

thermostat sticking?  Not fully opening?

[chimp koose]

doing a flush and thermostat tomorrow when parts arrive . I found crap floating in the coolant so I must have plugged off the thermostat or some tubes in the rad