Hey, I have a 1997 Ford Ranger 4x4 with a 4.0. Starting from when I got the truck it had a nasty red/orange rusty color in the coolant. We flushed it many times but it always came back. Now the truck started saying it was over heating. This would only last for seconds. It would shoot up to the red then instantly cool off to normal temp. Then the radiator cap blew fluid everywhere. So we replaced the radiator and thermostat. Now there is bubbles in the overflow and it's smoking bad. So my dad says its a blown head gasket. does that sound right? if so should I get it fixed of get a new motor for just a grand more with a 3 year warranty?