Very little heat

[chrisire]

2001 Expedition 4.6 L.....I replaced the radiator almost two years ago. Ever since then I have had very little heat inside my Expedition. Engine comes up to temp the way it should. I have checked the blend door and it's good. I have had the flow rate into and out of the heater core and it is good. Is there a second coolant flow control somewhere in the system that could impede coolant flow. Rear heat is as bad as the front heat. I really need help with this one guys?????

 

[ExpeditionLova]

Tryed replacing thermostat?

 

[ExpeditionLova]

And when u chcked the blend door did u inspect heater core

 

[stamp11127]

Check the temp of the heater hoses into and out of the front heater core with the engine at operating temp. Both should be hot. If not, check the flow from the engine to the core. If it is low it may indicate a water pump that has a few vanes missing.

 

[chrisire]

Have replaced the stat twice...just in case the first one was bad. When I checked the blend door, you ask if I checked the core...how do you mean??? I have installed an inline coolant pump which should take care of a water pump concern. Could a missing vane be blocking something internally in the block cooling jacket?

 

[stamp11127]

A dislodged vane could block the flow but most that I have seen have rusted away.

In order to check the flow to the core first step is to check the hose temp once the engine is up to operating temperature. The hand grab will suffice. Both should be hot. If there is a difference, the core or hose restrictor is plugged. If both are cold there isn't any flow.

To check a t-stat, boil some water with the t-stat in the pot. Once it gets close to the boiling temp you will see it open. If it doesn't it is bad. If it does, wait for it to cool off and reuse.

When you replaced the t-stat, how much crap did you see in the cooling system?