It could just be something as simple as the engine fan and wind on moving/driving the truck, causing coolant to be pushed towards the back of the engine from the tstat housing.
On sitting, this can then run down from the back of the block or wherever.
Coolant has an uncanny knack of "moving around" and leaks can be notoriously difficult to locate where it's coming from.
Hope this helps?
Al.

 

also something to add, it only leaks when it's just sitting and cold. once it's at operating temperature and runnning/pressurized, it's fine. But sitting and cold, it filled a paper plate in one day.

 

I may be a lowly 2nd gen Ram guy, but if you think its coolant ( I mean smell doesnt tell you what it is?) why dont you take the truck to a car wash and clean the engine bay and when you get home pressure test the cooling system to see the leak?

They make these, and you can either buy them or rent them from a parts store:
That would be my first step into finding the leak. Another thing though, if your leak is really bad, I mean the whole radiator draining out in one day, this test might not work.

 

well it's not any kind of oil, has water viscosity, and is an orangish color. Only leaks when unpressurized.

???

 

Wait wait..back this story up!

You got how many miles on that Hemi? And it's still running? Damn, I was under the impression these motors are only good for 90k or so.

 

160,000 and still haulin mail. er i mean 800 pounds of medical tools and equipment from hospital to hospital.

Dad is a regional service technician for belimed infection control systems. before that he was working for berchtold systems. Before was doing the booms/lighting/camera/ect systems (installing and servicing) and now he does the parts cleaners and all the infection related stuff. Keeps a good 500-800 pounds of equipment, including a hand operated folding forklift, under that tonneau, depending on the job.

 

Hum, Im not sure what your problem could be, but you should have flushed the cooling system somewhere around 100k. Going on 160k, a couple more months, and you would have been doing a second coolant flush for that hemi. Well, just something I should inform you about....

 

eh, the (locally owned and managed) oil depot never asked him if he wanted it done. We let them do scheduled servicings....they make alot of money off fleet vehicles. Our whole family is on first name basis with the owner. But a flush isn't too far away, for sure.

Should i suggest for the depot to do a backflush of the heater core, for the heck of it?

 

Man, who told you that? Mine will have 100K in a few months, and turns low-to-mid 7 0-60s. Many members here and other forums are past 150K. There's no reason these (or any motor) couldn't go a quarter-million miles with proper maintenance.

 

any more constructive theories?