 Our Explorer got warm once . Gauge shot from normal to 3/4 of the way up then went down, then shot almost to the red. I pulled over added water after waiting 45 minutes to cool engine (cool winter night) . There was no more overheating indicated & was driven a few more milesbefore the engine seized without Any indication of anything wrong . Dealer says piston is fused to block & will cost $ 5,100 for New ford engine, doesn't mention about the cause of the problem, most likely the Manufacturer Defective Radiator or the Head Gasket is to blame from my researchon this Model/Year (06/07) of Ford. Transmission is sure to go out soon I fear