Good morning.
Just to clarify, this isn't a high-efficiency furnace, so there's no condensate issues with the heat exchanger. The exhaust stack is old-school metal and quite hot. (When it's running)
Well, a "watched pot never boils" applies here. I re-assembled the Inducer Assembly, and mounted it back on the Bryant to test out 280's suggestions. And now the furnace is running like a champ. It got down to 49 in the house, we were running space heaters, empty electric clothes dryer load with the vent disconnected back into the basement, and excuses to bake a lot of stuff in the oven just to keep it at that point... so the priority for right now for the furnace is to just keep it running and warm up the house.
So now I see two possibilities.
1. The motor's bearings. They're not exactly sealed, but non serviceable either. So, I lubed the bearing points on the motor as best I could anyway. I floated some Mobil 1 in there with a little PB Blaster to wick it in there. It does seem to be running quieter. So to me, that means it was the motor. And it'll probably fail again sooner or later because I'm sure my temp lube job is not going to be adequate. This'll be an easy enough fix since I'm now familiar with taking apart the Inducer Assembly.
2. It is the gas valve solenoid assembly like 280 suggests, but with the furnace being off and "resting" for 10 hours overnight, it's working again for now.
Although, I'd think, that the longer the gas valve solenoid is held open during this long call for heat that's going on, and the longer it keeps running fine, the more likely it is to be the inducer motor.
Am I off-base on thinking this?