My '93 Accord has been putting out more water vapor out the tailpipe than normal for wintertime and slowly loosing coolant. If the car has been driven for a while, turned off and let sit for 10-15 minutes and restarted, it sends out a huge cloud of steam that takes ~20 seconds to stop blowing out. So I would assume its a blown head gasket which would be a real bummer since I replaced it and had the head machined flat last year when the head warped and the gasket leaked. I tested the compression of all the cylinders and they're all 170-180psi. The temerature guage hasn't gone past halfway since the summer and the cooling fans work.
The radiator gets topped off before I drive anywhere, and the reservoir above the 'min' line. When I get back to my car after letting it sit for hours the reservoir is full and the radiator is low. The radiator is an AutoZone one with that uses its own cap design so it won't take an OEM one, but it seemed to work fine drawing coolant back in during the summer. Cranking over the engine when cold pressurizes the radiator and bubbles come out of the reservoir tank's internal hose. I can also hear water gurgling behind the dash after I refill the radiator and start the car. Oil dipstick pulls up black oil.
I drove the car on wheel ramps, disconnected the ignition and cranked the engine over with the radiator cap off and coolant shot three feet in the air. Again that would point to a head gasket. Out of curiosity I tried to find out which cylinder was leaking. I removed one spark plug, turned over the engine several times with the cap on, then slowly opened the cap to see if there was pressure building in the radiator. Then I replaced the plug and tried the other three cylinders in turn. The radiatior was being pressurized no matter which plug I removed.
The front passenger side footwell has been soaking wet recently but I don't know for how long. It doesn't smell like antifreeze, and when I pulled up the carpet there is rusty cracks in the sound damper tile pasted to the floor. I don't see any rust on the underside of the car. The water could be coming from the heater core, the sun roof, or somewhere underneath the car.
So most things point to another blown HG. The heater core could be leaking which made the engine overheat and warp the head, and when the cooling system cools down it sucks in air from the leaking heater core instead of the reservoir. Then again air was getting pumped into the coolant with the spark plugs removed, so how else can the engine force air into the cooling system? A crack in the head between the exhaust and coolant?

P.S. What is the black plasitc duct coming from underneath the center of the dashboard and running on the floor on the right side of the center console to under the seat? Is it the 'recirculate' intake for the climate control?