I know this is a cooling issue but I'm thinking this is an engine block problem. I just got another Ford (67 Galaxie 500) with a 390 that was sitting for years so I'm told. The water pump was replaced by me since the weep hole leaked as were the radiator hoses. The car overheats after driving about 20 miles on a cool day. The radiator flows as seen by the water I poured through it when the lower hose was off. There are no leaks so far. I pulled the thermostat cover to replace what I hoped was a stuck thermostat only to discover there wasn't one. I left the new one out thinking the previous owner might have known something I didn't. The heater blows cool air even when car starts to overheat. When I pulled water pump to replace I saw there was no water to the heater. Haven't checked the heater hoses since the replacement water pump but the heater still blows cool. Is there a possiblity the coolant sitting in the block for years clogged the block? Is there something I can pour into the radiator to soften the deposits in the water passages? Any ideas? Could the radiator still be bad even if water flow through freely? The motor is coming out and going into my truck and the truck is getting sold. I want to sell a good running truck not one that over heats.

 

How did the coolant look when you changed the pump?

I would get a flush kit and give it a through flush followed by burping the system to make sure you don't have an air pocket in there. After that you can check your heater hoses to make sure hot coolant is flowing to the core. If one of the hoses is hot and the other cold then the core is blocked.

 

When I changed the water pump there was no coolant. Only water with some black stuff that looked like chunks of ash or something. I'm taking the radiator to get rodded (sp?) and then replace the heater core. Is there a way to flush the block without damaging the new/repaired parts?

 

Unhook all the hoses, restrict the lower hose and fill the block from the top (themostat opening). Open up the lower rad hose and let the water flow out. If the rear of your engine sits low you will still have some residue in the back of the block. You may want to do it a couple of time and see how clean the water is. This is not a flush but it should get most of the chunks out before you hook up all the new parts.