When driving my 1964 1/2 Coupe, I consistently feel a hot spot of air just above the steering column. Couple of things I am fixing: the heater plenum chamber (a cheap cardboard one) is ripped. Will be putting a new one in shortly. The shifter bezel has no brushes or barriers around the shifter shaft. Will be replacing that as well.

Any ideas as to what might be causing this?

 

As in the top of the dash? Yeah, there's a defroster grille there, and if the blend doors of the heater are badly adjusted or the foam seals are shot you'll be getting full-time airflow through the heater, some of which is bound to come out through the defroster. You'll need to remove the heater to replace the plenum anyway, so spend the extra $12 for the seal kit and do it right. The cables will need to be reattached when you put it back in, so that problem takes care of itself.

 

Nope. Not on top. No heat coming out of the defroster. It is in front of the cluster, above the steering column.

 

OK, that means the firewall seal at the column, or master cylinder, or clutch rod, or throttle is shot. You might even have extra holes from some past mod, such as AC, manual choke, etc.

 

Hmmm...now that I think about it, I could see space around the accelerator pedal shaft. Not sure about the column or master cylinder. No clutch. It is an auto. I'll check those areas again, but positive there is a gap at the accelerator. Might explain the exhaust smell I am getting in the cab, too...

Thanks, man.