The motor will not warm up on 2000 Ford Ranger

Motor will not warm up but it is still pushing a gallon of water in to the overflow bottle.We have changed the radiator cap and put fail safe thermastat in it and the took care of the problem for 2 months and now it is doing the same thing again any help would be great

Asked by for the 2000 Ford Ranger
1 answer
Sounds like the thermostat is stuck open, which is what these brand of thermostats will do if the engine temperature reaches a certain specification. I would get a thermostat from Ford and see if that fixes your problem.