ok, replaced the "T" intersection in the line, and still it only blows out luke-warm air for about 10-20 seconds, then gets cold, if you turn off the heater for a minute or two, it will blow out luke-warm air for 10-20 seconds, and get cold again.
I removed the liner for the glove box and checked to make sure the door is moving, I checked it by using the CC Unit(60-90 degrees) it moves like it is supposed too, I even disconnected the rod to make sure that it is fully on the hot side, and it still has the same problem. so we can rule that out.
I my 85 olds regency had this same problem, I replaced the heater core, and it still worked like it did before, no difference.
I find it odd that the coolant hose from the block to the radiator stays cold until the cooling fans kick on at 220, maybe the T-stat isn't opening correctly??,
I replaced the radiator a few months ago, and the coolant is still relatively green(and, yes I added GM coolant tabs!) looking at the coolant, it doesn't appear that the coolant has sediment in it,
So I think I'm gonna replace the T-stat, only 7 bucks anyways. Is there anything else that could restrict flow in these cars?