Hi guys, I’m a new member so this may have been answered before. Anyone that can lead me in the right direction will be greatly appreciated, I’m stuck. First off I do have this posted in the Expedition forum as well, I’d just like as much feedback as possible. So I just bought a 1999 Expedition with the 4.6 to run in the winter instead of my 98 F150. I noticed the vehicle had no heat, it seemed like it was just blowing cold air. So the first thing I did was change the thermostat. Problem continued. I flushed the heater core twice, didn’t seem like much sludge was coming out. I did realize the top radiator hose always appeared to be soft. I did come to find out the blend door was indeed stuck closed, so I fixed that. I filled the radiator and actually filled the top radiator hose with fluid, this caused it to seem like it was building some pressure. Doing this also caused it to have little heat which was better than before. I checked the vehicle today after it sat all night, I can squeeze the top radiator hose shut. Is this an airlock or a possible head gasket problem? It seems to be losing pressure. Thanks

 

What kind of shape is the water pump prop in ? Does it still have one lol. Yea they disintegrate down to nothing and why you check them every flush. No circulation , = very poor heat.

There are quite a few threads going on this topic, - how did you go about burping, did you use the Ford published procedure ?

 

Very easy to feel the heater hose going into the firewall.. if it’s not hot at operating temp..problem with circulation..if it is hot.. problem with heater core or blend door.

 

I have absolutely no pressure in the system. The water is luke warm. The only way to get hot water in the top radiator hose is pump it by hand. I can actually squeeze the top radiator hose shut while it is running. I had the vehicle jacked up as high as I could to try to eliminate an airlock. I can take the reservoir cap off anytime I want, no sign of pressure. I sprayed soap around the cap to see if air was coming out, zero. The bottom radiator hose is ice cold too, can squeeze it shut. What could cause this??

 

If i was to track it down, i would start with the cap- it doesnt sound like its building pressure, then i would go to the thermostat- it doesnt sound like its getting up to proper temp., then, if nothing else worked, i would change the water pump-although ive not experienced it- the impeller vanes can wear down over time.
Hopes this helps- regards, Bear

 

Sounds like an open thermostat. We tend to think of the thermostat as part of the cooling system but it is actually a part for generating heat. It's supposed to stay closed until the coolant gets hot. Yours must be opening too soon, or never closing.

 

I'd take up Jbrews suggestion. Look at the water pump.