No. There's no smoke coming from my exhaust. I mean...there's some white exhaust when I first start the truck in the morning, but as I drive the white exhaust fades away for the rest of the day. So I'm thinking that's just water vapor that accumulated through the night. Basically, the exhaust is clean...if u don't count the CO, heh heh.

Yesterday (when the engine was cool) I added antifreeze to the overflow tank up to the "cold fill" line, as suggested, and once again I added antifreeze to the radiator up to about an inch from the pressure cap. As I drove, I could still hear water running under my dashboard whenever I went up a hill or went from 0 to 'bout 50 (basically, whenever I wasn't at crusing speed). Today (when the engine was cool), I checked the antifreeze level in my radiator and it dropped about 2 inches. The level of antifreeze in the overflow tank is still the same (at the "cold fill" line). The mystery continues...any thoughts?

I don't know if this helps, but I'm wondering if this coolant problem has something to do with a "gap" in the radiator coolant reservoir thats between where I actually pour my coolant and the reservoir's housing. The gap seems intentional (it doesn't look like the gap was "formed" by expansion/contraction from heat), however, antifreeze DOES get in the gap whether I pour the antifreeze in it or if antifreeze overflows into it due to pressure. Is that gap a problem? Here's a picture to help better understand it...sorry if I sound more worried than I should be, heh heh