96 Ranger 2.3L No heat

[warhawk]

The truck has a new thermostat, antifreeze, heater control valve. If I use the heat control knob I get no heat. but both hoses are very hot as they should be going to the heater core. and the heater control valve is working. So I am wandering what does that heater control knob operate.

Thanks,

 

[srteach]

The heater knob controls an airway gate in the plenum.
If you have no heat, the most likely problem is an air bubble in the heater core, causing no flow through it.

If the system is clean, a few cold starts will burp the system.

This is from experience with a 96 2.3 engine.

 

[AllanD]

IF the heater core had a bubble in it that would only generate a gurgling sound.

NOT prevent water from circulating.

It's not a syphon, water is FORCED by all the might and fury of the water pump through the heater core.

Do understand that water constantly flows at moderate velocity through the heater core flow path

the water pump sucks it from the heater core pumps it into the block,
up into the head and back out to the heater core.

Coolant ONLY flows to the radiator when the thermostat opens

I think you've got a blend door malfunction

BTW, this is a heating & AC issue, not an "interior" issue.

AD

 

[srteach]

allan is correct, but there is very little force applied through the coolant to the heater core when the thermostat is open. When it is closed, all the coolant flows through the heater core. That is why I suggested a few cold starts.