It's been pretty warm here since I've been into this issue, but the vent temp comes down with decreasing outside temp. It's still been hot when I've tried it at a lower temp, but the vent comes down what seems to be the appropriate amount.

Remember, I don't drive this car everyday. I did try running it with the climate control off and did have some air coming into the passenger compartment at speed. There's no doubt that I am getting outside air.

My situation has changed just a little. I was planning on doing this job this weekend, but at the last minute I decided to order a heater core and replace it while I'm in there. I had a small leak in it some time ago and patched it with bars leaks.

The heater core was shipped airborne, and I don't think airborne will be able to find my corner of the boondocks today.

To change things even further, a business trip has come up and I have to drive to the SouthWest corner of Missourri on Monday. I got some metal film duct tape (real duct tape) and I am going to tape over about 80% of the cowl grill. I will then drive and check vent temp. If the vent temp comes down as I fully expect that will confirm that I'm getting fresh air. I am already completely convinced though.

I just don't want to tear it apart without all the parts that I expect to need on hand. If I have everything, then I can probably do it in a weekend. Even if I have everything, I'm not going to do it this weekend knowing that I need the car on Monday.

Have a great day,

Actually looks like we're going to get a little bit of relief for the weekend. A weak cold front, some clouds, and winds out of the North-East are supposed to keep temperatures in N. Texas in the low 90s Saturday and Sunday. May not have been the worst weekend to work on the car...

Larry - You may need to acquire some o-rings to replace the heater core. The hot water supply and return pipes bolt to the heater core and are sealed with o-rings. Not sure if they're of the corner store variety or not. You'll want to have them on hand to avoid surprise down time.

- JimY