maxf15 - sometimes in these long discussions we lose sight of the underlying issues. In looking back thru this string, correct me if I'm wrong I see:
1. coolant leak confirmed around viscous heater gasket
2. coolant drip onto hot surface but not located
3. #3 and 4 injectors wet around base but no comment on what the wet is
4. white smoke/vapor that smells of unburned? diesel and increases after initial startup but goes away after engine reaches operating temp (ambient temps on site in middle? GA in the 40-70F range)
So to address each item separately
1. this is a pricey part which doesn't do much in your location and only helps a bit in colder areas. If it was me I'd - pull the viscous heater relay (R36 in the black plastic power distribution center forward of the battery) to disable the viscous heater clutch; grab an appropriate length/size of heater hose; reroute flow from tstat directly to the heater core inlet pipe thus bypassing the viscous heater. No more coolant = no more leak.
2. could be coming from a variety of places which includes a leaky heater core dripping out of the HVAC drain on the firewall below the coolant tank. If you cannot find it with a flashlight then try so coolant UV dye and a UV light (former local parts store, latter same or Amazon).
3. probably diesel fuel leaking past copper crush washer. May or may not relate to #4. For ca. $20 (
http://idparts.com/catalog/product_info ... ts_id=3284) get 2 sets of replacement "O" rings and crush washers; install and see if leak and white smoke/vapor goes away.
4. your initial smoke/vapor looks just like my son's 06 in similar temps but his stops before getting a couple of hundred yds down the road and my 05 doesn't do that at all and neither do the billowing white thing. I'm guessing way rich on fuel during coldish start could be #3 as mentioned, could be leaky injector(s) pooling fuel but I'd think that would burn off quickly, could be injector(s) over fueling due to injector issue or bad ECU command for some reason. Not sure how to test for the latter but there is a leaky injector test that you can run - see 06 FSM pg 14-35 or 05 FSM with picture key pg 14-47 or how to; some bits of vinyl hose and 4 glass or plastic vials with quantity marks you can make will substitute for the referenced Miller tool.
Unfortunately, this leakage test is only for fuel-return leakage which would result in reduced injection pressure (you may have noticed the fuel return lines are rubber) - it does not address leakage past the needle\nozzle seal into the cylinder, of which we are possibly concerned - this leakage can be checked only in a BOSCH, BACHARACH, STANADYNE, or other injector tester at rail pressures
Unusual failure would be internal blocked fuel-return passage, such that injection pressure could not bleed-off, which would promote needle\nozzle leak - a specific volume of bleed-off is inherent in injector design - again, testable only in an injector testerYes check air box for critter stuff and/or dirty air filter.