Heater Problems

The reason that you are not getting enough hot air is because the lever is stuck or the lever it isnt getting enough pressure to be pushed open. First check to see if the nut(or screw) that holds the lever in place is too tight.

Actually, it could be a number of things. On older cars I suspect that your are getting warm coolant to the core, but not enough for good heat. make sure the heater control valve is opening all the way. You can do this by bypassing it and seeing if you get more heat that way. Also, it's real common that heater core plug up after a while. Try flushing it and back flushing it. Also make sure all your doors and lever are working correctly and sealing when they close.

I am assuming your ingine is running at full temp, so try those other things first.

I have the same problem. BUT, I have yet to really get into it. It seems as though there is air trapped in mine as I just put in a new core. If air is trapped (in the hoses as well), it won't allow the coolant to circulate through the core. This could be it.

I believe I saw someone post a couple weeks ago that opening the radiator cap will allow air to escape as it warms up and circulates. Be sure to add coolant/water as this happens.