Heat not heating

[randyj68]

I hope this is the right place for this, had a couple posts a while back, but here is the deal. I have a 68 Ranger, 390, 3 speed. Brand new radiator, heater core, thermostat and heater control valve. The truck runs cool as a cucumber BUT I have little to no heat. The fan runs properly on all speeds, the cowl is clean, the heater box was cleaned when I replaced the thermostat, tried the control valve in both heater hoses and no difference.............ANY ideas?

[Montana71-F100]

The problem with mine was that the "T" near the water pump was plugged with what looked like hard salt. I have no idea what it was. You could feel the heater hoses to see if they are hot. I think I'd drain the radiator enough to disconnect the hoses and blow through them to see if there is any obstructions.

Good luck

[fireguywtc]

I agree, check all junctions such as the "T" fitting, fittings coming from water pump and into the top of the intake. Once you know all is clear then we can move on because it sounds like most of your basic problem areas are already fixed.

I have two questions for you; what temp. rating is your new thermostat and did you do a flush recently before or during your repairs. If not it is possible that you washed old debris into your new heater core causing it to plug up.

[woods]

Maybe a weird air pocket that is stuck.

[basketcase0302]

woods on Thu Jan 26, 2012 10:42 pm
Maybe a weird air pocket that is stuck.

Not ever discussed much here through the years but I agree 100%. On airboats we'd put a "burp valve" similar to an old style radiator drain into the top of the intake manifold. This also made it so...much easier if you ever had to drain the coolant and then refill to get all the air out. The little air pockets Woods described do find their way into the engine causing some pretty crazy symptoms.

[Ranchero50]

Yep, half slplit the system, if the hoses are hot it's in the box, if the hoses are cold it's in the plumbing...

Jamie

[crazyhorse]

What has already been said.
Could the heater hose's have been reversed?
Could the thermostat be upside down?
Just trying to offer some ideas.
Good luck.