No Heat on 90 Lumina Sedan

I have a 90 Lumina Sedan and the heater does not work.
1.)the engine heats up fine
2.) Changed themostat
3.) The lines to and from the heater core are cool to the touch after the engine is hot
4.) The flap in the inside of the car opens and closes
5.) No noticable vacum leaks.
6.) I can blow air through the heater core- does not seem to be clogged
7.) coolant system bled
8.) I am stumped

In other words...there is not coolant flowing through the heater core hoses. I have removed the hoses and blew air through them and the heater core to make sure they were not clogged.

Any ideas? Is there a control value some where?

Is your lumina the 2.5 L four cylender? If so, I had the same problem in mine. If you follow the hoses back to the engine, one of them connects to the intake manifold. There is a threaded connecter that the hose plugs into - mine was L - shaped. Remove the hose from this end and there is a rubber plug in the fitting with a small hole in the middle, mine had swelled shut. I just removed the rubber plug and VOILA, HEAT! You may have to remove the fitting to get the plug out. I don't know about the V-6 engine, but I would imagine that there is one in the same place on there also.
Good luck !
Michael

If both heater hoses are cold then you have a blockage going to the heater core. Does you car have a heater coolant flow control valve. Check both heater hoses all the way to the engine and see if there is a control valve in the heater hose. If there is make sure its working.

I'm sorry, I forgot to mention it is a 6cyl 3.1

I blew air through the heater core and hoses, does not seem to be clogged.