I have owned Ford Rangers most of my life and never had a problem like this. It started about year ago when I was not receiving heat from the vents. In response to this I had my coolant system flushed and the problem seemed to go away. Then at the end of this summer my engine started to overheat occasionally so i had the thermostat replaced and the coolant system flushed again. This did not alleviate the problem. One day at the very end of the summer i pulled into my driveway and heard a loud thud, so i popped the hood and my coolant reservoir had popped its top and sent antifreeze all over the engine. The antifreeze had changed from a clear green color to an opaque brown color. I then looked into the problem and decided to replace the thermostat again and the radiator cap. This did not help the problem either so i replaced the cylinder head, head gasket, radiator and the water pump. I just finished the last repairs and refilled the coolant and upon taking a short 2 mile drive the reservoir had filled with coolant and almost exploded and coolant was leaking from the radiator cap and thermostat gasket. I have no clue why my engine is doing this will some please help me!!


Since then I have:

• flushed the cooling system 3 times,
• replaced thermostat 2 times,
• replaced the water pump ,
• radiator,
• cylinder head,
• head gasket,
• radiator cap.

 

This sounds to me like some kind of blockage. I know that the hoses going to the heater core get very brittle and pieces in those hoses can cause problems. They can even cause some blockage in the engine coolant ports. I would check into this. I would replace the heater core & core hoses, but leave the hoses disconnected at the engine. Make a T connection where the heater hoses connect to the engine, whit a shot off valve at the end of the T for a drain. You can get a T valve at any auto parts, in the coolant section. Now take the truck and have the engine pressure flushed,(not the radiator), And ask the person doing this to pay close attention if there seemed to be any blockage and let him know about the T valve you installed in may help in flushing the engine! After all is flushed have (him) connect your heater hoses, and fill the coolant, He will get all air out. Remember resivour should only be filled to levels indecated on side, hot and cold fill lines. Hope this helps. Like I say, sounds like a blockage.